SSRS How to pass subtotal value in matrix into another table just for display?

Hi all,

I have two matrix with subtotal for two grouping. I need to pass the value of this two group subtotal into another matrix table to display and perform simple calculation to get the differences.

How can I pass the subtotal amount into the other matrix?

In Crystal report I can define two variable where i can set the total to the value and call the two variable anywhere in the same report. But how can I do it in SSRS?

Appreciate can help

Thank you