How I Unleashed World War II, Part III: Among Friends(1970)

Original title: Jak rozpętałem drugą wojnę światową: Cz. 3 - Wśród swoich

Disguised as an Italian medic, Dolas finds himself on a ship evacuating wounded Axis soldiers to Italy. He leaves the ship disguised as a Nazi soldier, but is found out, declared a deserter and sent to the Eastern Front. However, on the flight to Russia, he is able to escape with a parachute, and finds himself back in Poland, now occupied by Nazis.