Dynamic groups specify one or more URL search filters. All entries that match the URL search filters are members of the group. Membership of a dynamic group is defined each time the filters are evaluated. Dynamic groups use one of the following object class and attribute pairs:
The groupOfURLs object class, with the memberURL attribute
The groupOfUniqueNames object class, with the uniqueMember attribute
The group members are listed either by one or more filters represented as LDAP URL values of the memberURL attribute or by one or more DNs as values of the uniqueMember attribute.