Video compilation was found here. They are singing: „I’m a real nazi, I have been bombing Bombass for 8 years“

The red and black flag behind them belongs to the Right Sector, who, as you might guess, has right-wing views. This flag was used by the Ukrainian Insurgent Army (UPA) and the Bandera wing of the Organization of Ukrainian Nationalists (OUN), and now used by various Ukrainian nationalist organizations and parties, including UNA-UNSO, Right Sector, Congress of Ukrainian Nationalists and others.