This one I remember from Smash 4 on WiiU. It’s based on Mario Kart 8 on WiiU (and now Mario Kart 8 Deluxe on Nintendo Switch) on the Mario Circuit track of that game.
You can easily tell as the karts in the background often race upside down. You basically fight on a moving platform.
Until you reach the end of the “track” and it starts over again.
While far from my favorite, it’s a decent stage. A great homage to the Mario Kart series.