Replay a slide with layers and/or ainmations without setting it to its initial state

I am working with another ISD that wants to include a course tracker that, I am told, requires all slides be set to remain in their resumed state.  This makes it hard, but I am hoping not impossible, to allow course participants to replay a slide or layers, if required (using a replay button).  I can replay audio on a slide without layers or animations, but can't find a solution for when layers or animations are involved.

Can you manually restart a timeline?  If not, can you use triggers to replay a layer's timeline or, at least, audio for multiple layers?  If no to both, any other ideas?