Not totally sure of what you want to do, but it seems like you could use something we call site partitioning. In the Community platform you can specify multiple "sites" - be aware this is not IIS sites, but rather a way of partitioning user data. In the admin interface you can create several sites. For almost all the methods in the community there is an overload that takes a Site, passing in NULL will be the global site, but you could also pass in a "sub site".
Maybe this could help...
We want our community to have specific forums, galleries etc. for each market/language, but all modules seem to be global in nature. Is there a good way to have a synchronised (but translatable) forum tree for all markets, but with specific forum posts for each?