Jason Cockington has a workaround:
At a recent training course, one of the students asked if it was possible to add two different columns on the legend of a line chart, so that when a selection is made on a second slicer the chart splits to reveal multiple lines.
Given others in the class showed interest in the subsequent conversation, I decided to create a short blog so that everyone could benefit.
The short answer is “no” but the longer answer is more interesting.