Nowadays most phones are out with trending 18:9 aspect ratio display, and this cause no navigation and physical keys available on all full-view display phones. In this situation, Gestures are more useful to easily navigate Home Key and Capacitve Key. Apple has early introduced all new Gestures with iPhone X, now Xiaomi is also replacing all Navigation keys with this Gestures.
These gestures are already enabled on Xiaomi Mix and Redmi Note 5 Plus, Now company has released a Beta update in order to enable on all new Xiaomi Redmi Note 5 Pro. However, this update is only for those who have already joined Beta Phase. The regular user cannot install it on their phone because it is not a stable update which may contain some bugs.
But if you are a beta user and you want to install it on your phone, then you will able to use this Gestures which allow you to use all three navigation key.