Sorry if I was unclear
this is the setup: (reducing the number of "real" chapers to 4)
M1 contains buttons C1,C2,C3
C1 short scene as a place holder for Chapter 1
M2 contains buttons Ca and Cb
C2
C3
Ca
Cb
works in studio (playing it as a DVD) but when played as iso file or hardware DVD pressing C1 button leads to:
jump to C1 and play this short scene
then jump to primary menu (M1) i.e. refuses to enter M2
should I construct this differently ?