When you unlink an account to your Shared Space, you will automatically remove all your transactions and balances associated with that account from that Shared Space.
Follow these steps to unlink an account from your Shared Space:
Tap on the dropdown profile bar in the top left of your screen.
Tap on the Settings for the Space you want to link an account to.
Tap on Linked Accounts
Deselect and unlink the boxes you want to share with your partner.