did the Nazi military have a special forces group? (other then the SS)?

Answer 1

Three "special forces" come to mind, the Grossdeutchland, Panzer Lehr and Herman Goerring divisions were elite divisions of the Werhmact. I don't know of any smaller groups except:

You're probably thinking of small groups such as the Brandenburger Commandos who achieved at most regimental size. The history of the Brandenburg Regiment ended in late 1944, but they had earned more decorations and mentions than any other unit of similar size in the entire German army. Their tactics were what later influenced such organizations as the US Navy's SEALS.

Answer 2

The Einsatzgruppen