Calculate currency exchange in budgeting

Continuing the discussion from How can I calculate total budget allocated:

Hello, Thank you members i was able to calculate total in my budget,

Now I have another question.
I want to use Currency Exchange Rate when creating budget.

Like how it is when creating Purchase invoice or Sales Invoice, there is an option to change Currency, and automatically total is calculated based on currency exchange rate.

How can I achieve something like that upon creating a budget?