If you know that only some of the users in your LDAP database should be known to the application, one way to get that subset is to create an LDAP group (such as "Jive SBS users"), then filter off that group attribute for users. Here's an example:
(&(sAMAccountName={0})(memberOf=CN=applicationUsers,OU=ExampleGroups,DC=example,DC=com))
This way you don't have to create any new OUs or move records around. You can simply modify group membership attributes on the user, something the LDAP administrator can do.