While not quite historically accurate, this is the Sable/Reich rank equivalence table used in the Sable Game.

Sable Army
Royal Air Force
Sable Royal Navy Haimat/Auslands-Heer
Luftwaffe
Heimat/Auslands
Keigsmarine
The Schutzstaffel
Field Marshal/
Marshal of the RAF
Admiral of the Fleet Generalfeldmarschall Grossadmiral Reichsführer-SS
General Admiral Generaloberst Generaladmiral Oberstrgruppenführer
Lt General Vice Admiral General (der Flieger) Admiral Obergruppenführer
Major General Rear Admiral Generalleutnant Vizeadmiral Gruppenführer
Brigadier (General) Commodore Generalmajor Konteradmiral Brigadeführer
Colonel Captain Oberst Kapitän zur See Standartenführer
Lt Colonel Commander Oberstleutnant Fregattenkapitän Obersturmbannführer
Major Lt Commander Major Korvettenkapitän Sturmbannführer
Captain Lieutenant Hauptmann Kapitänleutnant Hauptsturmführer
Lieutenant Sub-Lieutenant Oberleutnant Oberleutnant zur See Obersturmführer
Second Lieutenant Midshipman Leutnant Leutnant zur See Untersturmführer
Regimental Sgt Major Warrant Officer 1st Class Stabsfeldwebel Stabsfeldwebel Sturmscharführer
Colour Sgt Major Warrant Officer 2nd Class Oberfeldwebel Oberfeldwebel Hauptscharführer
Sergeant Major Chief Petty Officer Feldwebel Feldwebel Oberscharführer
Sergeant Petty Officer Unterfeldwebel Maat Scharführer
Corporal Leading Seaman Unteroffizier Matrosen-Obergefreiter Unterscharführer
Lance Corporal Able Seaman Obergrenadier Matrosen-Gefreiter Oberschütz
Private Seaman Grenadier Matrose Schütz

*Note, the historical SS rank of Oberführer (senior colonel) does not exist within the Sable Game; the lowest SS general officer rank is Brigadeführer.