Well sure. One of my cats is crazed about things that scurry under other things, especially under carpets, and will ignore a string or bug until it disappears under the edge of something and go into a sudden diving assault, burrowing under or flipping over rugs. He and other cats I’ve had have also demonstrated going under things to hide. Where’s the cat? Oh, that lump in the bed… [human lifts blankets one at a time] ... nope, cat is under the bedsheet, somehow. Oh, and my cheeto-obsessed cat will knock over my dustbin to get the empty bag of cheetos to snag the last crumbs… though I’m sure he can also smell them… but he also hops on my desk to peer down into the bin to see if it’s worth raiding, even when there’s nothing good in it.
And squirrels? I remember when I was a kid and a friend thought it was brilliant to stash food in the woods near our house, in a hidden niche in a tree. Not only did squirrels find it, they ate through all sorts of sealed packaging. Of course they might have learned anything like a human package is liable to be openable for food. Or they might just be able to smell food even through air-tight packages. But I’d say the concept of something being inside something else is firmly understood.
In all of those cases, the animals cared about the thing by themselves. In some animal intelligence tests, the humans assume the animal will react to an experiment in the way they’re interested in. The book I linked talks about the need to observe and study a species long enough to have a good sense for how they relate to situations first.
As for finding one’s way back, many animals have shown inexplicable ways to find places, even that they’ve never been to before. People also tend to assume that animal cognitive abilities will be inferior to ours, and that we understand the material world and what’s possible or not nearly completely, but there are quite a few animal behaviors that humans don’t know how they work at all, and that seem impossible from our material models of how things work.