Inner join header table information to tablix group by in SSRS


i've got an issue, i have 2 tables (datasets) in ssrs report in d365, one table is header information, another is lines,

in ssrs design i've got:

header - with information from header table with First() function it all expressions,

body - tablix with group by on ProdId with rows information showing on separate pages, with page break on each group i mean based on ProdId,

I need that on each page header of the report would correspond and show information about that group from body, currently it shows the first ProdId data

how is this achieved ?