How to Performe bank reconciliation For Factoring company?

Dear Experts,

I have two legal entities and two Separate Ledgers called A&B, Both companies generate invoices for same customers and customer pays money for Company A(Factor). At the end of certain period Company A pays outstanding money to company B and recognized this process more similar to the factoring process. I Just wanted to know how to plan receipt creation and bank reconciliation processes for company A.

Example:

Customer ABC purchase goods from both companies and invoice values as follows,

Company A:2000

Company B:1000

Company A received a payment Of 3000 how can we record and reconcile this customer payment in company A (Factor Company)