mapping

I want to use group policy preferences to map two network locations.  The first one is pretty straight forward for home directories \\servershare\users\%username%.  This works fine.

For the second mapping I want to map to a folder called depts \\servershare\depts.  This also works fine. This group policy is applied to a top level OU callled users-network.  under the users-network OU there are other OUs for the departments in our organization.  On the depts folder I assigned rights to authenticated users so all authenticated users can access the depts folder with special permissions for the depts folder.  I assigned full rights to any folder under the depts folder using groups created in the OUs under users-network.

Since the GPO is applied at the top level OU (users-network), when a user logs in he will see his home directory, and the depts directory and all the other department folders, but he only can open the folder assigned to his department.

Is there a way to have a GPO at the top level OU that maps to depts, but only show the folders that the user is supposed to have access to?