

The simplest is just sewing a strip onto the back at two ends, making a loop for the belt. If you’ve a bigger piece of leather, you can make a wing on each side with a wide hole that the belt can go through. Or the other direction, up, then loop back down and sew or rivet to the bottom.
Didn’t make this, so only a guess, but the concept of plants “communicating” via mycorrhizae is probably why it’s there.