Remove Single Filter Context?

Here's a simple example that best illustrates what I'm trying to do:

In this sample table of data displayed, I understand that each line has a context that relates to the numbers and measures that appear on that row.  The far-right column is a measure that should count the distinct number of "WH" values (column 3) in the current selection context, ignoring ONLY the current row's WH value context.  Thus, all values in the last column should be "1", with the exception of Part 341023, which should have a value of 9 in each row (as there are 9 distinct WH values).  I've tried ALLSELECTED, ALL, ALLEXCEPT, and a few other methods in conjunction with CALCULATE and DISTINCT COUNT but I can't figure out how to remove the measure's reference to only the WH context for each line.  Please Help!  Thanks.