diff --git a/ctldap-config.js b/ctldap-config.js
index 4fd12ff..5212a7e 100644
--- a/ctldap-config.js
+++ b/ctldap-config.js
@@ -28,23 +28,28 @@ export class CtldapConfig {
         this.ldapPassword = config.ldapPassword;
         this.ctUri = config.ctUri;
         this.apiToken = config.apiToken;
-        this.specialGroupMappings = config.specialGroupMappings || {};
+        this.specialGroupMappings = config.specialGroupMappings;
+        this.specialUserAttributes = config.specialUserAttributes;
         this.dnLowerCase = CtldapConfig.asOptionalBool(config.dnLowerCase);
         this.emailLowerCase = CtldapConfig.asOptionalBool(config.emailLowerCase);
         this.emailsUnique = CtldapConfig.asOptionalBool(config.emailsUnique);
+        this.filterInvitedPersons = CtldapConfig.asOptionalBool(config.filterInvitedPersons);
+        this.virtualRoleGroups = CtldapConfig.asOptionalBool(config.virtualRoleGroups);
+        this.skipEmptyGroups = CtldapConfig.asOptionalBool(config.skipEmptyGroups);
         this.ldapCertFilename = config.ldapCertFilename;
         this.ldapKeyFilename = config.ldapKeyFilename;
         this.ldapBaseDn = config.ldapBaseDn;
         // Configure sites
         const sites = yaml.sites || {};
         // If ldapBaseDn is set, create a site from the global config properties.
-        if (config.ldapBaseDn) {
-            sites[config.ldapBaseDn] = {
-                ldapUser: config.ldapUser,
-                ldapPassword: config.ldapPassword,
-                ctUri: config.ctUri,
-                apiToken: config.apiToken,
-                specialGroupMappings: config.specialGroupMappings
+        if (this.ldapBaseDn) {
+            sites[this.ldapBaseDn] = {
+                ldapUser: this.ldapUser,
+                ldapPassword: this.ldapPassword,
+                ctUri: this.ctUri,
+                apiToken: this.apiToken,
+                specialGroupMappings: this.specialGroupMappings,
+                specialUserAttributes: this.specialUserAttributes
             }
         }
         this.sites = Object.keys(sites).map((siteName) => new CtldapSite(this, siteName, sites[siteName]));
diff --git a/ctldap-site.js b/ctldap-site.js
index c696ed3..c61e33d 100644
--- a/ctldap-site.js
+++ b/ctldap-site.js
@@ -23,7 +23,8 @@ export class CtldapSite {
         // Take ldapUser from main config if not specified for site.
         this.ldapUser = site.ldapUser || config.ldapUser;
         this.ldapPassword = site.ldapPassword;
-        this.specialGroupMappings = site.specialGroupMappings;
+        this.specialGroupMappings = site.specialGroupMappings || {};
+        this.specialUserAttributes = site.specialUserAttributes || {};
         this.dnLowerCase = CtldapConfig.asOptionalBool(site.dnLowerCase);
         this.emailLowerCase = CtldapConfig.asOptionalBool(site.emailLowerCase);
         this.emailsUnique = CtldapConfig.asOptionalBool(site.emailsUnique);
diff --git a/ctldap.js b/ctldap.js
index daa7db6..f885f6c 100644
--- a/ctldap.js
+++ b/ctldap.js
@@ -7,6 +7,7 @@
  * @licence GNU/GPL v3.0
  */
 import fs from "fs";
+import jp from "jsonpath";
 import ldapjs from "ldapjs";
 import { CtldapConfig } from "./ctldap-config.js";
 import { patchLdapjsFilters } from "./ldapjs-filter-overrides.js";
@@ -163,8 +164,13 @@ async function fetchMemberships(site) {
   const result = await site.api.get('groups/members', {
     searchParams: {"with_deleted": false}
   });
-  logDebug(site, "fetchMemberships done");
-  return result['data'];
+  logDebug(site, "fetchMemberships done, found " + result['data'].length + " memberships");
+  const memberships = [];
+  result['data'].forEach((m) => {
+    m.groupId = 'g' + m.groupId
+    memberships.push(m);
+  });
+  return memberships;
 }
 
 /**
@@ -174,12 +180,20 @@ async function fetchMemberships(site) {
  */
 async function fetchPersons(site) {
   const data = await fetchAllPaginated(site, 'persons', { limit: 500 });
-  logDebug(site, "fetchPersons done");
+  logDebug(site, "fetchPersons done, found " + data.length + " persons");
   const personMap = {};
   data.forEach((p) => {
-    if (p['invitationStatus'] === "accepted") {
-      personMap[p['id']] = p;
+    const filterInvitedPersons = (site.filterInvitedPersons || ((site.filterInvitedPersons === undefined) && config.filterInvitedPersons));
+    if ((!filterInvitedPersons) || (filterInvitedPersons && p['invitationStatus'] === "accepted")) {
+      if (p['cmsUserId'] === ''){
+        p.cmsUserId = (p['firstName'] + '.' + p['lastName']).toLowerCase()
+          .replace('ö', 'oe')
+          .replace('ä', 'ae')
+          .replace('ü', 'ue')
+          .replace('ß', 'ss');
+      }
       p.dn = site.compatTransform(site.fnUserDn(p['cmsUserId']));
+      personMap[p['id']] = p;
     }
   });
   return personMap;
@@ -191,15 +205,30 @@ async function fetchPersons(site) {
  */
 async function fetchGroups(site) {
   const data = await fetchAllPaginated(site, 'groups', { limit: 100 });
-  logDebug(site, "fetchGroups done");
+  logDebug(site, "fetchGroups done, found " + data.length + " groups");
   const groupMap = {};
   const sgmKeys = Object.keys(site.specialGroupMappings);
   data.forEach((g) => {
+    
+    if (site.virtualRoleGroups || ((site.virtualRoleGroups === undefined) && config.virtualRoleGroups)) {
+      g['roles'].forEach((r) => {
+        // Create new Group for each role
+        const s = {};
+        s.dn = site.compatTransform(site.fnGroupDn(g['name'] + ' ' + r['name']));
+        s.id = 'r' + r.id;
+        s.name = g['name'] + ' ' + r['name'];
+        s.information = g.information;
+        const info = s['information'];
+        s.specialClasses = sgmKeys.filter((k) => info[k])
+        groupMap[s['id']] = s;
+      });
+    }
+
     // Strip some irrelevant information
     delete g['settings'];
-    delete g['roles'];
     // Pre-compute the "distinguished name" of this group for LDAP
     g.dn = site.compatTransform(site.fnGroupDn(g['name']));
+    g.id = 'g' + g.id;
     const info = g['information'];
     g.specialClasses = sgmKeys.filter((k) => info[k])
     groupMap[g['id']] = g;
@@ -229,6 +258,24 @@ async function fetchAll(site) {
     const [personMap, groupMap, memberships, groupTypes] = await Promise.all([
       fetchPersons(site), fetchGroups(site), fetchMemberships(site), fetchGroupTypes(site)
     ]);
+
+    if (site.virtualRoleGroups || ((site.virtualRoleGroups === undefined) && config.virtualRoleGroups)) {
+      memberships.forEach((m) => {
+        const n = structuredClone(m);
+
+        Object.entries(groupMap).forEach(([key, g]) => {
+          if (m.groupId == g.id) {
+            g.roles.forEach((r) => {
+              if (m.groupTypeRoleId == r.groupTypeRoleId) {
+                n.groupId = 'r' + r.id
+                memberships.push(n)
+              }
+            });
+          }
+        })
+      });
+    }
+
     // Create membership mappings
     const g2p = {}, p2g = {};
     memberships.forEach((m) => {
@@ -249,6 +296,14 @@ async function fetchAll(site) {
         }
       }
     });
+    if (site.skipEmptyGroups || ((site.skipEmptyGroups === undefined) && config.skipEmptyGroups)) {
+      Object.entries(groupMap).forEach(([key, g]) => {
+        if (!(key in g2p)) {
+          logDebug(site, "Removed empty group: " + g.dn);
+          delete groupMap[key]
+        }
+      });
+    }
     return { groupTypes, g2p, p2g, personMap, groupMap };
   });
 }
@@ -266,6 +321,13 @@ function requestUsers(req, _res, next) {
     let newCache = Object.entries(personMap).map(([id, p]) => {
       const cn = p['cmsUserId'];
       const email = site.compatTransformEmail(p['email']);
+      const extraattributes = {};
+      Object.entries(site.specialUserAttributes).forEach(([key, value]) => {
+        const uvalue = jp.query(p, value);
+        if (uvalue.length !== 0 && uvalue[0] !== null) {
+          extraattributes[key] = uvalue;
+        }
+      });
       return {
         dn: p.dn,
         attributes: {
@@ -291,7 +353,8 @@ function requestUsers(req, _res, next) {
                 .flatMap((gid) => groupMap[gid].specialClasses)
                 .map((key) => site.specialGroupMappings[key]['personClass'])
           ],
-          memberOf: (p2g[id] || []).map((gid) => groupMap[gid].dn)
+          memberOf: (p2g[id] || []).map((gid) => groupMap[gid].dn),
+          ...extraattributes
         }
       };
     });
@@ -340,8 +403,8 @@ function requestGroups(req, _res, next) {
         attributes: {
           cn,
           displayname: g['name'],
-          id,
-          nsUniqueId: `g${id}`,
+          id: id.replace(/^g/g, ''),
+          nsUniqueId: id,
           objectClass: objectClasses,
           uniqueMember: (g2p[id] || []).map((pid) => personMap[pid].dn)
         }
diff --git a/ctldap.yml b/ctldap.yml
index 3bfadac..ef2ea41 100644
--- a/ctldap.yml
+++ b/ctldap.yml
@@ -14,6 +14,12 @@ config:
   dnLowerCase: ${IS_DN_LOWER_CASE:true}
   # This is required for clients that need lowercase email addresses, e.g. Seafile
   emailLowerCase: ${IS_EMAIL_LOWER_CASE:true}
+  # Hide persons with an invitation status not accepted
+  filterInvitedPersons: ${IS_FILTER_INVITED_PERSONS:true}
+  # Create additional virtual groups for each role within a group. For example, for the group 'Event A' with the roles 'Head' and 'Participant', create the additional groups 'Event A Head' and 'Event A Participant'.
+  virtualRoleGroups: ${IS_VIRTUAL_ROLE_GROUPS:false}
+  # Hide groups without any member.
+  skipEmptyGroups: ${IS_SKIP_EMPTY_GROUPS:false}
 
   # LDAP admin user, can be a "virtual" root user or a ChurchTools username (virtual root is recommended!)
   ldapUser: ${LDAP_USER:root}
@@ -43,6 +49,12 @@ config:
       groupClass: NextCloudGroup
       personClass: NextCloudUser
 
+  # This map can be used to add special attributes to the user. They can also get dynamicly from the user
+  # by jsonpath (https://github.com/dchester/jsonpath#jsonpath-syntax) to the array returned by the API.
+  # To get an example you can access https://mysite.church.tools/api/persons?limit=5
+  #specialUserAttributes:
+  #  age: '$.age'
+
   # To use SSL/TLS, provide file names for x509 certificate and key here
   # Use this command to create a private key and a certificate:
   # openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 365
@@ -69,4 +81,6 @@ sites:
 #    specialGroupMappings:
 #      nextcloud:
 #        groupClass: NextCloudGroup
-#        personClass: NextCloudUser
\ No newline at end of file
+#        personClass: NextCloudUser
+#    specialUserAttributes:
+#      age: '$.age'
diff --git a/package.json b/package.json
index 25959b3..64ababd 100644
--- a/package.json
+++ b/package.json
@@ -14,6 +14,7 @@
     "@node-rs/argon2": "^1.5.2",
     "@node-rs/bcrypt": "^1.7.3",
     "got": "^13.0.0",
+    "jsonpath": "^1.3.0",
     "ldap-escape": "^2.0.6",
     "ldapjs": "^3.0.5",
     "tough-cookie": "^4.1.3",