Eventually it will. But there’s a bug preventing global search working in lemmy itself. You can see more of the details here (github.com/marsara9/lemmy-search/issues/20 )
One of my primary goals with this is that users MUST be able to open a given link in their home instance so that they can then interact / reply / subscribe, etc… without having to figure out how to find said post themselves. So with that requirement, users MUST select a home instance but because of the before-mentioned bug I can’t show posts that your instance isn’t aware of.