Hi Community,
I have a SharePoint List named Header and another SharePoint List named Details. Header is a report header which has fields such as Title, HeaderID1, TotalClaimAmount, ClaimSubmission Date. Details shows the individual expense items under the header.
In PowerApps, I have a HomePage screen shown below. The gallery is from Header. The idea is that once I click on ">" icon, it will bring me to another screen with individual expense details from the report.

This is what I get when I click on the Homepage to navigate to the report details. The bottom half of the screen is a gallery with datasource Details. It should extract from Details all the expense details under the same report. All expense details are set to have the same ID as the report they are under.

Under Total Claim Amount, it should display the total claim amount shown in Header, after doing a match between the ID under Summary.Selected and HeaderID1 under Header.
I do not know how to write the formula for this. I tried Filter(Header, Summary.Selected.ID = Header1) but I do not know how to include TotalClaimAmount in.
Kindly advise. Thank you!