Jews. Mostly as guards of concentration camps. Jews of course were not foreigners. They were as German as anyone else.
It would be interesting to understand why a Jew would act as a guard in a a concentration camp; a place where his kith and kin were persecuted. The most opportunistic types. Those who prefer to survive without any principles, perhaps?
What were the Japs doing here? They could have well served in their nation's army. Some kind of exchange? Or were there Japanese people in Germany in large numbers?
This Japanese is an officer in the German army
Indians. Efforts of Subhash Chandra Bose.
Bose was anti-British. He met Hitler in Berlin and raised the Indian unit in the Wehrmacht. Enemy's enemy is a friend, I guess.
Georgians and Azerbaijanis
One can understand the Chechen in the German army. Their struggle against Russia continues till this day.
Hitler shrewdly maintained good relations with the Arab world