diff --git a/src/test/java/de/muenchen/zammad/ldap/service/CreateGroupAndUserTest.java b/src/test/java/de/muenchen/zammad/ldap/service/CreateGroupAndUserTest.java
index a030f1f..2a6370f 100644
--- a/src/test/java/de/muenchen/zammad/ldap/service/CreateGroupAndUserTest.java
+++ b/src/test/java/de/muenchen/zammad/ldap/service/CreateGroupAndUserTest.java
@@ -1,12 +1,14 @@
 package de.muenchen.zammad.ldap.service;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import java.util.List;
+import java.util.TreeMap;
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -18,7 +20,10 @@
 
 import de.muenchen.zammad.ldap.domain.ZammadGroupDTO;
 import de.muenchen.zammad.ldap.domain.ZammadUserDTO;
+import de.muenchen.zammad.ldap.tree.LdapOuNode;
+import lombok.extern.log4j.Log4j2;
 
+@Log4j2
 @ExtendWith(MockitoExtension.class)
 @MockitoSettings(strictness = Strictness.LENIENT)
 class CreateGroupAndUserTest extends PrepareTestEnvironment {
@@ -26,6 +31,9 @@ class CreateGroupAndUserTest extends PrepareTestEnvironment {
     @Captor
     private ArgumentCaptor<ZammadGroupDTO> createGroupCaptor;
 
+    @Captor
+    private ArgumentCaptor<ZammadGroupDTO> updateGroupCaptor;
+
     @Captor
     private ArgumentCaptor<ZammadUserDTO> userUserCaptor;
 
@@ -53,4 +61,55 @@ void createTest() {
 
 	}
 
+
+	@Test
+    void createParentNodeTest() {
+
+        var zammadService = mock(ZammadService.class);
+        when(zammadService.getZammadGroups()).thenReturn(List.of( new ZammadGroupDTO("1", "1", "shortname_2_1", true, true, "lhmobjectId_2_1", null)));
+        when(zammadService.getZammadUsers()).thenReturn(List.of());
+
+        assertEquals(1, zammadService.getZammadGroups().size());
+        assertEquals(0, zammadService.getZammadUsers().size());
+
+        groupMocksCreateParentNodeTest(zammadService);
+
+        var zammadSyncService = new ZammadSyncServiceSubtree(zammadService, createZammadProperties());
+
+        var childTree_level_2 = new TreeMap<String, LdapOuNode>();
+        var number = 1;
+        var level = 2;
+        var dn = String.format("dn_level_%d_no_%d", level, number);
+        var child_level_2 = new LdapOuNode(dn, createEnhancedLdapOuSearchResultDTO(level,number), new TreeMap<String, LdapOuNode>(), null);
+        childTree_level_2.put(dn,  child_level_2);
+
+        var childTree_level_1 = new TreeMap<String, LdapOuNode>();
+        level = 1;
+        dn = String.format("dn_level_%d_no_%d", level, number);
+        var child_level_1 = new LdapOuNode(dn, createEnhancedLdapOuSearchResultDTO(level,number), new TreeMap<String, LdapOuNode>(), null);
+        child_level_1.setChildNodes(childTree_level_2);
+        childTree_level_1.put(dn,  child_level_1);
+
+        var childTree_level_0 = new TreeMap<String, LdapOuNode>();
+        level = 0;
+        dn = String.format("dn_level_%d_no_%d", level, number);
+        var child_level_0 = new LdapOuNode(dn, createEnhancedLdapOuSearchResultDTO(level,number), new TreeMap<String, LdapOuNode>(), null);
+        child_level_0.setChildNodes(childTree_level_1);
+        childTree_level_0.put(dn,  child_level_0);
+
+        log.info(child_level_0.toString());
+        zammadSyncService.updateZammadGroupsWithUsers(childTree_level_0);
+
+        verify(zammadService, times(2)).createZammadGroup(createGroupCaptor.capture());
+        assertNull(createGroupCaptor.getAllValues().get(0).getParentId());
+        assertEquals("shortname_0_1", createGroupCaptor.getAllValues().get(0).getName());
+        assertEquals("2", createGroupCaptor.getAllValues().get(1).getParentId());
+        assertEquals("shortname_0_1::shortname_1_1", createGroupCaptor.getAllValues().get(1).getName());
+
+        verify(zammadService, times(1)).updateZammadGroup(updateGroupCaptor.capture());
+        assertEquals("shortname_0_1::shortname_1_1::shortname_2_1", updateGroupCaptor.getAllValues().get(0).getName());
+        assertEquals("3", updateGroupCaptor.getAllValues().get(0).getParentId());
+
+    }
+
 }
diff --git a/src/test/java/de/muenchen/zammad/ldap/service/PrepareTestEnvironment.java b/src/test/java/de/muenchen/zammad/ldap/service/PrepareTestEnvironment.java
index fa34ac7..8a77884 100644
--- a/src/test/java/de/muenchen/zammad/ldap/service/PrepareTestEnvironment.java
+++ b/src/test/java/de/muenchen/zammad/ldap/service/PrepareTestEnvironment.java
@@ -65,6 +65,19 @@ protected void userAndGroupMocks(ZammadService zammadService) {
         when(zammadService.createZammadUser(new ZammadUserDTO(null, "vorname_2_3_1", "nachname_2_3_1", "lhmobjectId_2_3_1", true, null, null, "lhmobjectId_2_3_1", List.of(0, 1), Map.of("3", List.of("full")), null, true, null))).thenReturn(new ZammadUserDTO("6", "vorname_2_3_1", "nachname_2_3_1", "lhmobjectId_2_3_1", true, null, null, "lhmobjectId_2_3_1", List.of(0, 1), Map.of("3", List.of("full")), null, true, null));
         when(zammadService.createZammadUser(new ZammadUserDTO(null, "vorname_2_3_2", "nachname_2_3_2", "lhmobjectId_2_3_2", true, null, null, "lhmobjectId_2_3_2", List.of(0, 1), Map.of("3", List.of("full")), null, true, null))).thenReturn(new ZammadUserDTO("6", "vorname_2_3_2", "nachname_2_3_2", "lhmobjectId_2_3_2", true, null, null, "lhmobjectId_2_3_2", List.of(0, 1), Map.of("3", List.of("full")), null, true, null));
         when(zammadService.createZammadUser(new ZammadUserDTO(null, "vorname_2_3_3", "nachname_2_3_3", "lhmobjectId_2_3_3", true, null, null, "lhmobjectId_2_3_3", List.of(0, 1), Map.of("3", List.of("full")), null, true, null))).thenReturn(new ZammadUserDTO("6", "vorname_2_3_3", "nachname_2_3_3", "lhmobjectId_2_3_3", true, null, null, "lhmobjectId_2_3_3", List.of(0, 1), Map.of("3", List.of("full")), null, true, null));
+
+    }
+
+    protected void groupMocksCreateParentNodeTest(ZammadService zammadService) {
+
+      when(zammadService.createZammadGroup(new ZammadGroupDTO(null, null, "shortname_2_1", true, true, "lhmobjectId_2_1", null))).thenReturn(new ZammadGroupDTO("1", null, "shortname_2_1", true, true, "lhmobjectId_2_1", null));
+      when(zammadService.createZammadUser(new ZammadUserDTO(null, "vorname_2_3_1", "nachname_2_3_1", "lhmobjectId_2_3_1", true, null, null, "lhmobjectId_2_3_1", List.of(0, 1), Map.of("1", List.of("full")), null, true, null))).thenReturn(new ZammadUserDTO("1", "vorname_2_3_1", "nachname_2_3_1", "lhmobjectId_2_3_1", true, null, null, "lhmobjectId_2_3_1", List.of(0, 1), Map.of("1", List.of("full")), null, true, null));
+      when(zammadService.createZammadUser(new ZammadUserDTO(null, "vorname_2_3_2", "nachname_2_3_2", "lhmobjectId_2_3_2", true, null, null, "lhmobjectId_2_3_2", List.of(0, 1), Map.of("1", List.of("full")), null, true, null))).thenReturn(new ZammadUserDTO("2", "vorname_2_3_2", "nachname_2_3_2", "lhmobjectId_2_3_2", true, null, null, "lhmobjectId_2_3_2", List.of(0, 1), Map.of("1", List.of("full")), null, true, null));
+      when(zammadService.createZammadUser(new ZammadUserDTO(null, "vorname_2_3_3", "nachname_2_3_3", "lhmobjectId_2_3_3", true, null, null, "lhmobjectId_2_3_3", List.of(0, 1), Map.of("1", List.of("full")), null, true, null))).thenReturn(new ZammadUserDTO("2", "vorname_2_3_3", "nachname_2_3_3", "lhmobjectId_2_3_3", true, null, null, "lhmobjectId_2_3_3", List.of(0, 1), Map.of("1", List.of("full")), null, true, null));
+
+      when(zammadService.createZammadGroup(new ZammadGroupDTO(null, null, "shortname_0_1", true, true, "lhmobjectId_0_1", null))).thenReturn(new ZammadGroupDTO("2", null, "shortname_0_1", true, true, "lhmobjectId_0_1", null));
+      when(zammadService.createZammadGroup(new ZammadGroupDTO(null, "2", "shortname_0_1::shortname_1_1", true, true, "lhmobjectId_1_1", null))).thenReturn(new ZammadGroupDTO("3", "2", "shortname_0_1::shortname_1_1", true, true, "lhmobjectId_1_1", null));
+
     }
 
 
@@ -189,7 +202,7 @@ private Map<String, LdapOuNode> createNextDnLevel(Integer level) {
     }
 
 
-	private List<EnhancedLdapUserDto> createLdapOuUser(Integer level, Integer no) {
+	protected List<EnhancedLdapUserDto> createLdapOuUser(Integer level, Integer no) {
 
 	    var userNo = 0;
 	    var user = new ArrayList<EnhancedLdapUserDto>();
@@ -215,7 +228,7 @@ private List<EnhancedLdapUserDto> createLdapOuUser(Integer level, Integer no) {
 	    return user;
 	}
 
-	private EnhancedLdapOuSearchResultDTO createEnhancedLdapOuSearchResultDTO(Integer level, Integer no) {
+	protected EnhancedLdapOuSearchResultDTO createEnhancedLdapOuSearchResultDTO(Integer level, Integer no) {
 
 	    var ou = new EnhancedLdapOuSearchResultDTO();
 
@@ -253,4 +266,19 @@ protected ZammadProperties createZammadProperties() {
         return zammadProperties;
 	}
 
+	protected  Map<String, LdapOuNode> createChildLdapTree() {
+
+        var dn = "dn_level_0_no_1";
+        var rootNode = new LdapOuNode(dn, createEnhancedLdapOuSearchResultDTO(0,1), createNextDnLevel(1), createLdapOuUser(0, 0) );
+
+        var root = new HashMap<String, LdapOuNode>();
+        root.put(dn, rootNode);
+
+        log.info("Test groups created: " + rootNode.flatListLdapOuDTO().size());
+        log.info("Test user created: " + rootNode.flatListLdapUserDTO().size());
+        log.info(rootNode.toString());
+
+        return root;
+    }
+
 }