I’m not the owner / developer - I think a more general-purpose approach is required. On this particular discourse site there are many different languages with a number of topics in each. English has the most topics of course but it would be convenient to say check a box for Japanese-only topics.
I guess this would require a “Native Language” selection from a list in personal details for the user? - followed by the “Native Language Only” checkbox?
Further to that idea, I guess it would make sense to be able to select more than one language to show rather than topics to mute - is “mute all except”?