Selecting a single layer across all of its time without 'drag select'

This is more than likely a very simple thing to do but I cannot find a ‘hot key’ or any simple way to do it.

I want to select all the frames in a layer/multiple layers at a single time without having to select (what seems to be arduous) by running my wacom pen along each frame from 1-3000 frames within a layer/multiple layers which seems to chew up alot of my time.

Any assistance here would be greatly appreciated! Thanks :slight_smile: