Book on military hierarchy

[FM Paul Heinrik]

I was wondering if there is a well detailed book about the roles and functions of the different military ranks. More specifically, I'm interested in German command positions. Ideally, I could be able to look up for example, "Major-General" and see an outline of his staff's positions and duties, ect.

I'm interested in Nazi Germany, but any book on the subject would be fine as well.

Thanks