You are aware Ukraine only exists as a sovereign country because of the USSR right? Ukraine was never an independent nation before the USSR. The USSR gave many of the peoples and nations of the old Russian empire their own republics. It was a big part of the Soviet project. They had a congress that was democratically elected, but their version of a “senate” was actually a “nation and people’s” congress, where 2 representatives of each nation, ethnicity or people would gather and have the power to veto laws etc. like a senate does.