Capture Grouping Values

I have two groupings defined in my table. I group by Owner and then by Priority. I'm struggling with the expression to capture the string values at the appropriate scope. Using the table below, I want to capture "Critical, High" for "Jack Daniels" and "Medium, Low, Informational" for "Jim Beam". The table has "grpOwner" and "grpPriority" defined on Fields!Owner.Value and Fields!Priority.Value respectively. Any help would be greatly appreciated!

Owner

Priority

Jack Daniels

Critical

High

Jim Beam

Medium

Low

Informational

You should be able to concatenate the values in code as explained here.|||I opened a ticket with MSFT and they recommended creating a custom assembly with a function that retrieves the values based on the grouping level.