The Gruppe was commanded by the Gruppenkommandeur, whose rank was supposed to be that of Major. However, often people of lesser rank would be responsible for a Gruppe, several with rank as low as Hauptmann.
Other senior personnel in a Gruppenstab were:-
Gruppen-Adjutant - responsible for the same area in the Gruppe as the Geschwader-Adjutant - i.e. areas IIa (Personnel, officers) and IIb (Personnel, other ranks).
Hauptmann beim Stabe - responsible for the areas Ia (Operational questions) and Ic (Enemy activity)
Nachrichtenoffizier (NO) - responsible for communications and tactical recon.
Technische Offizier (TO) - responsible for the technical equipment, such as aircraft etc.
Gruppen-Arzt (IVb) was the doctor in the unit,
There were two people covering the area IVa (responsible for the other administrational task, supplies etc) and one technical official.
The Chef der Stabskompanie was responsible for the smooth running of the unit, and he had some 260 men to help him, the Werftzug (60 men), the Technisches Personal (30 men), the Nachrichtenzug (73 men), the Kfz.-Zug (33 men), the Flakzug (22 men) and other personnel (42 men).
The Gruppenstab had 4 aircraft, one Schwarm, and often a couple of reserves. These were usually flown by the Gruppenkommandeur and the other officers in the Stab, but also other personnel in the Gruppe were used if necessery to fill up the Stabsschwarm.
See also Geschwaderstab
Brekken, Andreas - Posting on the old TOCH board 26 May 2003