Google has been adding "interesting finds" to the search results since 2018. But now, if you click to show more results for interesting finds, Google will let you expand those results by related tags or topics. Glenn Gabe spotted this and posted an example on Twitter.
Here are some screen shots for a search on [google algorithm update dec 2020]:
After you click on the button at the bottom of this list to show more, then it takes you to this screen with the "Related" tags:
You can then click on any of those related options to see continues search results that Google would classify as "interesting finds."
Here are more examples from Glenn:
Well, this is interesting, pun intended. I'm seeing a test where Interesting Finds is showing related topics where you can view more Interesting Finds SERPs. Typically you see a single list of articles after tapping, but now there's an endless # of SERPs organized by topic: pic.twitter.com/tb7cxpUsIV
— Glenn Gabe (@glenngabe) January 6, 2021
Forum discussion at Twitter.