Try changing the value syntax of custom group

Author: tomdaley92

customGroup.xml

@@ -42,7 +42,7 @@
         <display>Members</display>
         <order>4</order>
         <page>1</page>
-        <value><![CDATA[=php.MultiList(/;(&(objectClass=posixAccount));uid;%cn% (%uid|-4%))]]></value>
+        <value><![CDATA[=php.MultiList(/;(&(objectClass=posixAccount));dn;%cn% (%uid|-4%))]]></value>
 </attribute>
 </attributes>