I know it's been talked about before but comments made indicate that the Expand Track Layers option was deliberately removed. However, according to the Help, right-clicking on the track header should still give this option.

This will be sorely missed by me if it doesn't get put back in. With two clips overlapping, the right-hand clip edge can be trimmed forward but the left-hand clip edge can't be trimmed back. Try it and you'll see what I mean. I'm going to have to separate the clips, trim the left-hand one, then pull the remainder back to overlap it again. What a shambles!!

EDIT:-

I've quickly found a solution (I think). I've just inserted a new video track and pulled the clip upwards into it. It means I'll have to do this to every other clip on the timeline but it's a solution at least.