A little complex but maybe you can do yours around this idea.
We set B and C timelines up so if their buttons are clicked the just reverse back to the start.
Their animations start well beyond the 0 frame so we should not see any animation when that happens.
When A time line is complete it tells timeline B to go to a point on the its timeline After the reverse action and pause. Once this happens the B button will continue the timeline in the normal direction.
The B timeline reaches it’s end and does the same for C.
You in effect have cascading timelines.
Cascading timeline buttons .hype.zip (18.7 KB)