How did the Gestapo find the Jews that were hiding during World War 2

Department B of the Gestapo were the German Police who were directly assigned to deal with Sects and Churches. This included Catholics (B1), Protestants (B2), Freemasons (B3) and Jews (B4). Department B4 of the Gestapo was specifically in charge of the discovery of the Jews that were hiding during WWII in Germany.

Department B4 of the Gestapo would often bribe and threaten other members of the community (sometime even including Jews) in order to expose their whereabouts.