Google Is Testing Ability for Users to Search Within Product Reviews

Google introduced the ability to search within local listing reviews a while ago and now it looks like they are testing this functionality within product reviews that they aggregate in SERPs. I think as a user this is going to be fantastic but sucks for those review aggregator sites.

I am able to see this feature from Australia as well, so it might be a rollout and not a test. Try searching for airpods.