So I found a solution. This is from Power Bi Tips. Filter a slicer with a slicer–What I did was on the Consultant page was put another slicer that contained all the population sizes–if the consultant wants to see cities data that are NOT members, they can click on the appropriate fields in the slicer. Otherwise, only the member categories will be selected. I have included my file again with the updated screens for anyone that may need this in the future. Thank you all for your help!
Sample File-Consultant-Members Demo.pbix (49.1 MB)