The Nearby tab pulls in your Preferred Languages setting on iOS. It will first search your first preferred language, then the second, and so on. If an article is available in your first and second language, only the first language will appear in Nearby. You can change the language for it within the article.
What if languages I don't speak are showing up?
It could be the case that a language accidentally got added to your preferred languages in the past. You can check and possibly remove these languages by going to Settings on iOS.
Go To General
Language & Region
There you will see your preferred languages with the ability to add/delete them.