Sadly the BG filter system does not usually work well for this kind of selection. I just tested it using URDU, which I don't read or speak, The Language index says there are three stones in URDU, but there are no listings for either Pakiston or India, which have this as an official language. I also tried it for US and UK, which have sizable ethnic populations from those Urdu speaking countries but nothing came up. It just kept giving me transcription choices in my local zone. All are in English.
A number of times users have asked BG to work on these filters and each time they fiddle with something and it works for a while, bu then goes buggy again.
I also just tested it with Russian and also got only 1196 Russian language returns, but it would not let me select a cemetery in any country, so the bugginess is back again.
I also browsed the map and I think all of those 1196 Russian stones are in one cemetery and it looks like the photograph/transcriber still has those within the 14 day window, so they would not come up for either of us. I browsed around and could not find any other open Russian/Russia stones available for transcription.
Also, with this sorting system, unless someone has already set the language field to Russian, it would not be able to find them by this method.
Maybe some other user knows a work-around; it may just be that there are not many photographers working in Russia, and thus no photos to transcribe.
I have often come across stones with Cyrillic alphabet, which I recognize, but not sure what is the base language, especially in cities in the northern US and Canada. Maybe you could look for these and transcribe them properly. They are often badly done by those who don't even recognize the alphabet!