Adding a calculated geomean field

[Sundar Iyengar]

Hi, I have tried hard to answer my question, but I have not been successful. The description of the problem and the question relates to the image below.

There are many regions. Only a few are selected based on Filters 1 through N. Only some of the products get selected based on the Product filter or value filter on Max of Price.
I am able to add a calculated item to compute the price difference between two products if they appear in the table ("Price-Diff 1" row). Likewise, I want to add a calculated field called "Geomean" which is a geometric mean of all values for each row that appear in the table. How do I add this geomean calculated filed?

The number columns (Region) can change based on Filters 1 through N. The geomean calculated field should include all visible columns and only those.

I am trying this in Power Pivot. I have tried Power BI, but the geomean DAX formula computes geometric mean for each column instead of each row. I can use either tool depending on which would allow me to add both the needed calculated item and field.

I'd appreciate any help you can provide.