Pivot Table Custom Calculation

[Oprichnick]

Hello,
I have a pivot table in which I want to have a sum shown as a percentage of subtotals.
It is quite simple to do it, however I want to apply filters... and when I apply them the prior calculation is lost.

Is there any way to maintain the percentage calculation of subtotals (including all labels) independently of what are the filters applied?

Thanks,
Pedor