This feature is available only on the Galaxy S7 and Galaxy S7 edge, unless Samsung ends up sending out a software update to enable the feature on other models. And if you want to share your mobile data signal with another device, all you need to do is disable Wi-Fi sharing by going to Settings > Mobile hotspot and tethering > MORE.
The feature will come in handy if you are connected to a Wi-Fi signal and want to share it with another mobile device, but you can't remember the password of the network. With Wi-Fi sharing enabled, using your phone to provide at free connection becomes a snap.
source: HDBlog.it (translated) via SamMobile