Setting Up Multiple Retained Earnings Accounts in Sames Chart of Accounts

If your requirement is to have P&L accounts X1 to Y1 carried forward to 1 retained earning account (R1)
and
X2 to Y2 carried forward to another retained earning account (R2)?

Then you can do this by T-Code OB53.
You can define 1 P&L statement account type to be "P", the account to be R1,
the 2nd P&L statement account type to be "Q", the account to be R2.

In the GL master (FSP0), you can define in Type/Description tab in P&L statement acct type "P" or "Q" to control the retained earnings account that the P&L account is carried forward to.