How to link the sales history from FG one to FG 2

Hi,

we have two FG codes, A and B. we need to club the sales history of B to A for some analysis.

Pls suggest  how can we do it. we are not using variant configuration function instead of that we are creating a separate code -which is B , similar to A.

while pulling sales history of A, system should club sales of A+B.

pls advise