Is there a way to find out whether those bus routes from Lviv to Poland still run? A route from Melitopol (conquered by Russia I know) appears to go through Ternopil. If you locate Ternopil bus station in Google maps, there are departure times for services to Warsaw
https://infobus.eu/en/bus/carrier/info-721/route
Update:
Ternopil to Warsaw bus service still runs, as per Ternopil bus station online board. In fact, the bus is listed as "on platform", but 0 empty spaces. More services to Warsaw are listed for later dates
http://bus.com.ua/cgi-bin/tablo.pl?as=610100