Show Foreign Currency Amount on Transactions

1. Navigate to Customization > Lists, Records, & Fields > Transaction Body Field > New
2. Enter a Name.
3. Select Type as Currency.
4. Set Store Value is No.
5. Under the Applies to tab select Vendor Payment.
6. Under the Display tab set Subtab to Main.
7. Under Validation and Defaulting tab set the following:
   Default Value - nvl({total}*{exchangerate}, 0)
   Formula is true.
8. Click Save.

Note: When the customer is paying USD to a Vendor who is billing in a different currency, the custom field shows the equivalent amount based on customer's currency.