public static List <Group> GetGroupMemberShip(GroupPrincipal groupPrincipal) { string[] paths = { AD.LDAPShort + "OU=OUGroepen" + AD.LDAPSuffix }; List <Group> allGroups = ADService.GetAllGroups(paths); List <Group> groups = new List <Group>(); foreach (Group group in allGroups) { if (groupPrincipal.IsMemberOf(group.GroupPrincipal)) { groups.Add(group); } } return(groups); }