Can I create an instant trigger that only works if another instant is activated?

So I want to create an interactive video with buttons in which each button would be linked to an animation. 

Say I have:

Start button.

Stop button.

Advance button.

Retract button.

The advance and retract motion buttons won't work unless you have the start button activated, and everything would reset back to original position if the stop buttom is pushed.

Is there any information on how to create conditions for certain instances to work and not work?