This is a Double-Pouch:
It is related to the non-orientable Projective Plane, but I compromise a bit to make it embeddable in 3-dimensional space.
I made it from a disk of denim. Fold the disk into quarters, then sew together three of the four edges.
Here the top edge, light in color, is free. If you lift the free edge and flip it over the tip, then one pouch closes and the other opens up:
Here is another double-pouch, somewhat bigger:
I made it by trimming, folding and sewing the following pattern. The Velcro strips are there for pouch closure.