I think it should be possible some kind of "browseable list = user1, user2,..." so an admin can decide which users can see the share resource and which not. For instance, it would be possible to share [homes] on a way that just some users can see their homes directories visible. This is useful if you are in a large organization with an Active Directory or an LDAP server centralizing your users, and your Samba is sharing [homes] for those users, but not for the entire organization, just for your department.