Communist PM of resistance to Germany was Josip Broz Tito (1943-1945) he was chairman of National Committee for Liberation of Yugoslavia who worked in opposition to Royal governments in exile.
Communist Yugoslavia
In SFRY, each republic had its own constitution, supreme court, parliament, president and prime minister. At the top of the Yugoslav government was a collective Presidency, the federal Prime Minister, and the federal Parliament.
The role of the prime minister was diminished by the fact there existed various other positions of importance, both nominal and effective. See also: history of Yugoslavia.