How is the retained earnings account created

 We are setting up one Ledger and one Legal Entity. Client has 5 companies (balancing segments), which will be assigned to the legal entity in the accounting set up.

The ledger set up requires a Retained Earnings account. If one company account is set up, what happens to the closing entry to retained earning for the other companies? For example, if company 10 Retained Earnings is entered in the Ledger set up, does the closing entry for company 20 go to company 20 retained earnings or does it go to company 10 retained earnings?