cross filter management (date range comparisons)

I have a bar chart with monthly totals (pageviews) and am using a cross filter to show monthly details of other metrics when selected.  I have a table including running calculations for each month (month over month percentage changes for each metric).  When the month is selected, I want only that month to appear in the table but the table calculations not to change.  For example, when July is selected I want to the table to display the percentage changes compared to the previous month (june) instead of compared to itself (as that is the only data not filtered out).