How do I make an auto walk path?

So, this is super dumb. But I cannot figure out how to make an auto walk path that actually works. I’m on switch. I’ve played some of the DS games, but it was when I was a kid so I didn’t discover the feature. Here’s the spoiler part: I want to make an auto walk path for the Explorers Guild trial to spend five days in B8F. So, can I make an auto walk path that just goes back and forth on the path near the dragon?