Right click on one of the measures on the rows/columns shelf and select Mark Type-->desired mark type. Notice, you will be able to toggle through on the Marks card to each different measure. Toggle through each measure and place both measures on the Level of Detail shelf. Now, when you hover over any point, both measures will appear. Hope this helps!
That's exactly what I was missing, scrolling through the mark types. Yeah! I'm going to learn this software yet.
If you don't need separate marks cards for the view, you can just place both measures on the Level of Detail shelf without first making it multiple mark types and get the all measures available to all marks.