Translation:The tourists are not in the Spanish bank, but in the Turkish hotel.
As a location, it means "by the bank", "next to the bank". But if you work "at a bank", you can also say it in Hungarian like that: "Egy banknál dolgozom."
So does this mean that "egy bankban dolgozom" means "I work in a bank," and NOT "I work at a bank?"
Let's say it is closer to "I work in a bank". It is more concrete, more specific, definitely.
When you say you work at such-and-such company, that is usually best translated with "-nál"/"-nél".
Well, there can be exceptions. The "-nál"/"-nél" suffix refers to a company, not a building. Some places are more frequently referred to as buildings, locations. Sometimes the two blend together because the distinction is not really important. Or both versions are used with a slightly different meaning. So, there could be a small confusion.