Buyer Commission

Hi;

We have scenario that Buyer A buy goods with Company A, company pay certain commission to buyer A. To achieve this we have created a buyer in AP to record his commission invoice as a liability.

At the same time buyer A introduces another Buyer B, company has to pay commision to buyer A of buyer B purhcases also. How can we record this scenario in AP so that we can  trace total liablity of A and and at the same time we can see the detail of how much is liable to buyer A on account of buyer B.