code: @Override
      public Set<Node> getUsersForGroup(Node group) {
  		Set<Node> users = new TreeSet<>();
  		try {
  			String query = "(" + groupIdentifyer + "=" + group.getName() + ")";
  			SearchResult searchResult;
  			Attributes attributes;
  			SearchControls controls = new SearchControls();
  			controls.setSearchScope(SearchControls.SUBTREE_SCOPE);
  			NamingEnumeration<SearchResult> results = ctx.search("", query, controls);
  			Node user;
  			while (results.hasMore()) {
  				searchResult = results.next();
  				attributes = searchResult.getAttributes();
  				NamingEnumeration<?> members = attributes.get(groupMemberAttribut).getAll();
  				while (members.hasMoreElements()) {
  					String memberDN = (String) members.nextElement();
  					String uid = getIdentifyerValueFromDN(memberDN);
  					user = getUser(uid);
  					user.setDn(memberDN);
  					users.add(user);
  				}
  			}
  		} catch (NamingException ex) {
  			handleNamingException(group, ex);
  		}
  		return users;
  	}
docs: Load all Users for a given Group.
  
  @param group the given Group.
  @return Users as a Set of Nodes for that Group.