The "Balances" option will show you a screen with two parts. The top part of the screen will show the balance from 150+ Days to the Current balance.
The bottom part of the screen will show this suppliers account balance history, month by month.
It is displayed by month/year and you can click on any month to see all the transactions for that period.
The Balances option is mainly used as a quick reference. You cannot change any of the balances from this option.