Long-time readers will be used to ‘yet another Google innovation’, but I do only bring you a selection of these. Many are previewed but never make it into the real world, so I tend to leave mentioning them until they actually start to appear in the search results.
That’s no reason to assume they’ll become permanent of course!
All of this is a preamble to mentioning the “Refine this search” and “Broaden this search” features, which are indeed now being seen in the wild, several months after being previewed.
What Google is doing with these suggestions is moving further into being a query-answering engine, which it clearly sees as the future (and indeed the present). As I see it, if our search is a query, it identifies where that query might be in a series of queries users might make, based on what it’s seen elsewhere and on its own AI. It then offers users the chance to get more granular (“Refine this search”) or to go back up the query chain (“Broaden this search”).
How should this affect our SEO? To be honest, I doubt there’s much we can do to exploit the new features. Just be aware of their existence, and once we start seeing them, constantly check searches that are important to us and see if there are new ideas in the new suggestions.