The best way is that you use the LDAPgroups, to control access to the BO Folder.
So, if you have a enterprise group G1 that has access to folder F1, make your LDAPgroup a member of enterprisegroup G1. Then all users from your LDAPgroup G1, will get access to the folder.
Then when new users are added to the LDAPgroup, they will automaticly get access to the BO Folder.