Bolivian Currency in Numbers

Works for me. I tried it with the region set to Bolivia and and then set to US. The only difference is that when the region is Bolivia it displays the currency in the cell as "Bs" instead of "BOB". In both cases I used "BOB" in the function.

I get an error that it does not have a conversion for that pair of currencies.

The function gets the conversions from Yahoo! Finance. There are often problems with missing data for stocks (also supplied by Yahoo! Finance) so I would not be surprised if there is missing data for currency conversions. With stocks, there will be days where some data is unavailable. It will eventually get fixed and work correctly.

If there is never a conversion of BOB to PYG, you can convert to USD first then to PYG.