Part of the organisation is splitting off. A new bank account has been created and a new business has already been set up in Manager.
While you can do transfers to different bank accounts in Manager for the same business, how do you record it when it is going to a separate business?
In the existing business create payment transaction from Capital account (equity).
In the new business you would record a starting balance in the bank account.
No, you should record a receipt in the new business and not use starting balances in cash or bank accounts. The new business did not exist before. So it is not being migrated.
This situation can be very complex and requires professional accounting advice.
I agree that you should seek professional accounting advice and if you require help implementing that advice into Manager make a further request based on that advice.