Complex sentence: A fire-brigade "Truppführer" may also act as leader of a self-contained "Feuerwehrtrupp," handling special missions and can proceed in the role as commander of the vehicle crew.
Split into simpler sentences: A fire-brigade "Truppführer" may also act as leader of a self-contained "Feuerwehrtrupp". He is able to handle special missions and can proceed in the role as commander of the vehicle crew.