Yes you can do it. You need to create a new sheet as in Screenshot below and create a view for the Region Only. Use this data set to create view.
ID Region 1 2 Central 3 East 4 South 5 West
Then create your main view
Float both sheets into a Dashboard and send the upper sheet to back using dropdown., but keep it's legend alongside main sheet. Don't use legend of main sheet in dashboard. You would get this:
Hope it Helps!!
Its working as expected
Great!!! Can you close thread by Marking it Helpful and CORRECT.