Since the Bank Register report is only able to show one bank account based on the Default Bank Account set in Home > Set Preferences > Reporting/Search, this is an alternate solution.
1. Navigate to Reports > Financial > Balance Sheet > Customize Detail.
2. Click Filters.
3. Expand the Financial folder on the left hand side of the report builder.
4. Expand the Account Type folder and click Long Name.
5. Select Bank in the pop-up window for its value.
6. Click Preview or Save.
The report will show all bank accounts and all the transactions depending on the date selected. Take note that the bank account will show its balance based on the base currency set in the Company Information page for single instance accounts. For OneWorld accounts, it will show the base currency of the Parent Subsidiary.