Chart Series display when two lists are on the rows of the grid.

Currently I can create a chart which has 3 items from one list (x) and 2 from another (y) on the rows. This will draw 6 lines on a line chart.

The issue is that the series only displays the members from the list x so I do not know which member from y the graph represents. The member in x will appear twice. If I highlight the line on the chart, it also reflects the series so doesn't differentiate.

It would be good if I could see member x and y combined so that they can be differentiated on the chart.