Complex sentence: An international organization, Kampfgruppe Auschwitz (Auschwitz Combat Group), was created in 1943, which, in 1944, together with the Home Army set up an overall Auschwitz Military Council to coordinate resistance.
Split into simpler sentences: An international organization, "Kampfgruppe Auschwitz" (Auschwitz Combat Group), was created in 1943. In 1944, together with the Home Army, the Kampfgruppe set up an overall Auschwitz Military Council to coordinate resistance.