The recently discovered patent shows outwards-folding sides akin to Xiomi's own foldable concept. There are important differences, however. Each of the foldable side seems to feature a battery pack, and the screen has a reinforced rear mid-section. There are no ports, buttons, or cameras suggesting that the model could feature wireless charging, gesture controls, and in-display cameras.
https://www.notebookcheck.net/Samsung-s-latest-dual-foldable-phone-patent-is-very-similar-to-Xiaomi-s-concept.415259.0.html