Can I prompt on a column in a Dashboard on a Combined Analysis pivot report when half of the values

I have a Combined Analysis report being used on a dashboard. Both analysis are using the Advanced Custom Object Active Subject Areas.  One gets information from Custom Object 4 (CO4) and the other has information from Opportunities.

The combined analysis are nearly identical but CO4 has a picklist field called Type (With values like: Partner, Competitor, Employee).  When combined with Opportunity this field doesn't exist and should be blank but I've hardcoded a value called (Primary).  I'd now like to add a dashboard prompt which will allow users to filter based on what Types they'd like to see.

I know the prompts need the same formula as the two formulas in the analysis.  How can I do this?  Below are some of the case methods I've tried below and my thoughts in italics.