See other domains thru a linux router

How do I enable domain browsing behind a NAT/Router setup linux box? Samba is on and had been set to forward WINS and DNS requests plus Router is set to forward DNS queries to the Domain controller in the network. But Client computers behind that linux box cannot browse beyond that and find other computers or domain out there without knowing the exact name of what you want to connect to. I would like to be able to just click on Microsoft Network and see all the domains out there, not just the samba domain I set up on the linux box.