I can't help you there, but once you find some places, please add them to the BTCmap for future reference, the community will appreciate.

https://paycek.io/shops
A list of merchants with paycek payment provider, they are not necessarily bitcoiners, on chain only for now.
Any region in particular?

telegram group for bitcoin only group in the balkans, might be useful to find tips from locals https://t.me/dvadesetjedan21

The island of Rab is meant to be a Bitcoin citadel. https://www.youtube.com/watch?v=07g3EuoSOGI

Konzum (biggest food retailer) accepts Bitcoin (and crypto), but via an intermediary (PayCek)