Hiding few forums

[Forum Lover]

Ok, here is the scenario, I got two languages in my forums.

Forum A, B & C is only for German language speaking people. Rest other forums are for everybody, generally.

So here what I want, for example,

If language id 1 selected then hide few forums for view & search.

If language id 2 selected then show all forums.



Where and what code I need to put? Thanks in credit.