code: public String getGroupMemberFilter(String groupMemberDN) {
          groupMemberDN = escapeSpecialCharacters(groupMemberDN);
          Object[] args = {
                            groupMemberDN
          };
          return new MessageFormat(iGrpMbrFilter).format(args);
      }
docs: Gets the LDAP filter expression for search groups a member belongs to.
  
  @param groupMemberDN The Distinguished Name of the member to find groups.
  
  @return The LDAP filter expression.