That's not really how the technology works. But a simple solution could be, both in kbin and lemmy, if the software could aggregate link posts that share the same canonical link URL and provide a summary for each community that's linked it. Then you'd see the link once, but could see the post from each community that's linked it rolled up underneath it.

Kind of like how some RSS readers have a feature that will detect "hot links" in your feed and surface the link with access to the feed items below it rather than having the feed items scattered about.