A given user can only select one currency for a Purchase Request (the main currency of the employee subsidiary). Is there any workaround in order to have multiple currencies per employee for a Purchase Requisition?

we created a custom field that lists other currencies, then wrote a workflow that copies the value of what is set in the custom field to the standard Currency field

Thanks @Lea CC I'm working with the idea of having a "previous step" form when I only ask for Subsidiary and Currency, then use that as parameter on the record load of a new Requisition... If my users find that solution too convoluted, I'm going to test your idea... Thanks again!!!

the available currency list depends on what currencies are available on vendor record. That's a standard behavior in any transaction, not only in Purchase request.