I have no idea how to "subscribe" to those. I don't know if it is a performance thing or what but when I search "all" for those communities within lemmy.one, they don't show up. It only shows communities within lemmy.one. I think it is performance issues because the drop down where "all" currently is has individual uhh....fediverses<?> listed.
for a given subreddit, you need to find its... url? not sure what it's called. for example "[email protected]" is the ukraine community on lemmy.ml. if you type this on your search bar in lemmy.one it should show up and you subscribe.
it seems even if just one person on your instance subscribes to a 'foreign' community, it will show up in your search results for "all".
Well, I am kind of an idiot I suppose. When you search, you have to add the ! in front of the community. It worked now and I am subscribed. Still getting used to all this.
Tell me about it...until this place picks up, I may have to continue to use reddit for r/ukraine and r/worldnews. Sometimes things are just that important. I can't stay in the dark.