Hi and welcome to the forum,
For the BdM / JM the triangle showed the
Gauverband (Nord, Ost, West, Mitte and Südost) and the Obergau (Mittelland, Westfalen etc). Later in the period, the Gauverband and Obergau were dissolved as organisational structures and so from then the triangle showed the same information as the HJ / DJ triangle i.e.
Obergebiet and
Gebiet. Over the course of the period the structure of the Hitler Youth grew; new Gebiete were created as Germany gained territory, some Gebiet names were changed and some Gebiete were split in two. Additionally, organisational structures called "Befehlsstellen" were created. You can see the result of these changes
here and also
here (Full Member
Gold subscription required). Essentially though, there were ultimately 42 different triangles of the following type:
You don't have permission to view attachments.
It doesn't stop there though. You can further sub-divide into early and late triangles (difference in font) and then you must consider the special triangles for musicians, those on the staff of the RJF, for Reichsdeutsche living abroad etc etc.
With the above in mind, Wim Saris, a member of this forum, has written an extremely useful
book that explains the large variety of triangles and I thoroughly recommend it. It is available from a few vendors so search for:
"Handbook of the Hitler-Jugend, Wilhelm P. B. R. Saris".