Calculated column (that uses Over statement) affected by a Filtering Scheme

I have a number of calculated columns that calcuate the parameters for the slope of a trendline of yearly data over multiple regions.  This "Over" statement results in one trendline for each region.

These calculated columns work perfectly except for when I apply a filter in my Filtering Scheme to limit the data; for example by filtering to show only a few years of data.  When the data is filtered, the calculated columns with the "Over" statements are unaffected by the filtering.

Any ideas how to refer to this filtering in the calculated column using the custom expression box?  Are there other work arounds?

(2) Answers