Is there a way to make the seekbar start over on a layer in SL2?
You mean put the seekbar on top of your layer, rather than having it as part of the player?
Not that I know of.
I want the seekbar to start over when it goes to a layer.
The seekbar starts when the layer shows.
It always restarts whenever you return to a layer if the layer property is set to Set to initial state on revisiting.
It frequently restarts whenever you return to a layer is the layer property is set to Automatically decide on revisiting.
If you want the user to be able to restart the layer's seekbar, go to player.
Choose Features and Allow user to drag seekbar
The user can either click on the seek bar, or click on the restart icon:
If you want the timeline (and therefore the seekbar) to begin again on layer A:
Layer B will show for such a short time that it won't be visible, but the timeline of Layer A will be restarted.