Multiple thresholds in foreground layer or multiple foreground layers

Hi!
I have a foreground layer where I want to make one threshold in the upper extreme values and a different threshold (with different colors) in the lower extreme values. In principle, I can see two different ways to do this:

  1. Setting two different upper/lower thresholds on the same foreground - is this possible?
  2. Adding two different foreground layers - is this possible?