Multilingual discussions

I have installed a translation package on top of the English default one. Now I'm trying to make discussions multilingual.

I managed to add a "language" custom data field to the Add/Edit/Search discussions forms, so users can tag their posts with the right language.

Where I struggle is to be able to filter discussions by language on the discussions home page, so users will see only the relevant discussions. I didn't find blocks to add in the page.