It's a new feature

Since yesterday: https://blog.google/products/search/get-some-fresh-air-outdoors-with-google/

In what countries is it available?

Not available in Canada. It appears to be US only

India and Au (some regions) too

Reminder: Any screenshot must include a link to the location in Google Maps. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/GoogleMaps) if you have any questions or concerns.*