Returning distinct count of filtered records

Here is my problem.

I have 2 columns (Rationale Documented & Role Name)

I need a formula that can filter the entire Rationale Documented column to identify when Rationale Documented > 0; then return a count of distinct Role Names found on the rows left in the filtered data.  I’ve tried all types of countif/countifs/sumx, etc… formulas.  But nothing I’ve come up with is getting me the result I need.

Using the example image, the result count I'm expecting will be 2. (FNC_ARASH_ARASH_ARASH_Performer_GO and FNC_IT_Christopher_Black_Team_Performer_GO)

Example

I also tried using DAX and creating a measure.  I'm open to whatever works.

Any help would be greatly appreciated.