Would that be the field under Server Manage, System Properties, ldap.searchFilter?
Yes. And also ldap.groupSearchFilter if your plans include groups integration.
I suppose any field in your ldap schema
as AD example: only members of Group1 (should work - not checked by me)
or in my case: only users with email field in AD filled in
Basically you have 2 approaches:
- edit ldap.baseDN to include only path to particular OU
- edit search filter
Please try browsing your ldap server either by freely available JXplorer, or by adsiedit included in windows administration tools(cd2). You will find more easily answers to your questions once you realize how simple ldap actually is.