Are you able to post a sample workbook (twbx file) to better explain the issue you are experiencing? Thanks!
I actually figured out a work around. Using a dual axis map, I plotted the PMSAs. On the other axis, I used a calculated field to plot the MSAs where there wasn't a child PMSA. It took a little bit, but I'm happy with how it turned out.
I would have preferred to be able to show the parent MSAs with the option of expanding them into the child PMSAs with a quick filter, but that doesn't seem possible. Maybe we can do that in the 22nd Century......
I got my PMSA lat/long from here:
MSA PMSA Map.twbx.zip 18.9 MB