I think this one is the tail gunner position of the Ju-288.
The Junkers Ju 288, originally known within the Junkers firm as the EF 074, was a German bomber project designed during World War II, which only ever flew in prototype form. The first of an eventual 22 development aircraft flew on 29 November 1940.
Although the 288 never even reached production status, let alone official operational service, the aircraft did see limited combat duty. In 1944, following the cancellation of the 288 program, the surviving A and C series prototypes were hurriedly fitted with defensive armament and equipment and deployed as reconnaissance bombers on the Western Front.
Very few missions were flown, owing to the scarcity of aviation fuel and spare parts, and the unresolved problems with the aircraft's powerplant and undercarriage. It is believed that the 288's were attached to the same unit operating the small number of Ju 388 reconnaissance planes that saw service.