This screen allows you to manage the bank account list which enables you to restrict the list of available accounts to a specific group when you are working in clusters. You can also add/edit/delete bank accounts. (Xero ones can't be deleted). These functions are accessed from the new Bank Accounts tab under Finance | Transaction processing. Generally you only need to access these if you are not using Xero unless you want to restrict a Xero bank account to a particular group.