Relation between A/c doc. number(BKPF-BELNR) and a/c doc. (J_1IPART2-FAWREF)

Dear Experts,

I am an ABAP developer working without any functional person for FI. Our accounts dept.person wants a list of all open accounting documents (BKPF-BELNR) with corresponding accounting documents (J_1IPART2-FAWREF).

Please refer below screen shots for both document numbers.

1. (TCode faglb03)

2. (tcode - J1IEX)

Kindly help to find the table relationship between these document numbers

Thanks,

Vishal