You can add sub currencies on Money Manager. The exchange rate is based on the internet and it will be updated once a day. You can also update manually by clicking the "Update" button.
Please go to Settings > Sub Currency Settings
You will see the "Update" button on the bottom, and it will be updated once a day when you click the button.
For example, you want to update the Canadian Dollar (CAD), click it, and then the page will move to like below. On this page, you can modify
1. Exchange rate
2. Unit Position and
3. Decimal point
Therefore, if you click the "pencil" icon that is top of the right corner, you can change the order of the sub currencies by dragging them or delete them.
Finally, on the entry page, you will see the sub currencies.