How can I sum the visible rows only, excluded the hidden row values in SSRS?

Hi, I have this problem in SSRS report. I have grouped my table to filter the duplicate data and stay hidden. My problem is that I need to sum all the values, even though some data are hidden the sum is still adding them up. Is there any way to solve this problem, wherein it will sum only the visible rows?

I’ve already tried other methods as I saw in other forums, but it doesn’t work.

Please help…thanks a lot.