Foreign Exchange is a Level 1 title for Reyna, a Governor in Civilization VI: Rise and Fall. In Civilization VI: Gathering Storm, its effect gets incorporated into her default title, Land Acquisition, thus removing it as a Level 1 title.
Since the creation of coinage, there has been an agreement that not everyone’s coins are valued equally. From this, the foreign exchange came into being, allowing traders to get locally-accepted currency in exchange for whatever coin they arrived with, usually allowing the exchanger to keep a percentage of the transaction. The English word “bank” derives from the Italian “banca,” which was the name of the counters where medieval money-men performed foreign exchange.