Making a selection to create multiple lines in graph to compare

Right now I have a slicer that provides information on multiple locations. Click on a location and it gives the data of that location on the graph. Click on multiple locations and it sums the data and provides that to the graph.

However, I would like the selecting of multiple locations not to sum them, but make seperate lines to compare them.

I know I am missing something really simple.  I just have a lot of data and want the end user to select what they want to compare.  Any ideas?