Start with the 20th century in Ukraine, the Holodomor.

Sochi was Circassian land, the descendants are mostly no longer anywhere in Russia

https://en.m.wikipedia.org/wiki/Circassian_genocide#:~:text=The%20Circassian%20genocide%2C%20or%20Tsitsekun,War%20(1763%E2%80%931864).

Then there is the Stalin era, that fits some, if not all, the characteristics (the Holodomor is part of it, so is Crimea, Dagestan and a few other forced internal population movements.

https://press.princeton.edu/books/paperback/9780691152387/stalins-genocides

This is a good start. Given the term genocide came from the Holodomor, there are others across Russian history. In general empires did this. So not exclusive to Russia. The difference is that other former imperial powers, or current ones, are facing to that history. Well, China is in the midst of one right now as well.