how to make a material be able to explode 2 bom at same time

Hello,

My scenario is, we have 2 finished goods A and B, they all are using same semi-finished goods S1, but this S1 has 2 versions of bom, one is component R1, and another is component R2. now how to let now A it extract raw material R1, and B extract R2. I tried explosion number, but it doesn't work.