Were your German ancestors deprived of their German citizenship by an official document during the Nazi era, or did your German ancestors leave the then German territory due to Nazi persecution and live abroad in 1941?
Then there may be a right to naturalization under Article 116 paragraph 2 of the Basic Law (GG).
Article 116, paragraph 2 of the German Constitution provides for the right to (re-)naturalization (so-called “reparation naturalization”) for former German citizens who were deprived of their citizenship for political, racial or religious reasons between January 30, 1933, and May 8, 1945, as well as for their descendants.
The Basic Law has always consciously accepted dual and multiple nationality for the purpose of rehabilitating the victims of National Socialism.