The Xbox Adaptive Joystick can be plugged directly into an console or PC and then linked up with other controllers for "full controller functionality", such as the Xbox Adaptive Controller where you can get a "full adaptive setup"
"Refine your gaming experience with the configurable, wired Xbox Adaptive Joystick – designed as a companion for the Xbox Adaptive Controller and other Xbox controllers (sold separately). Made to meet the needs of players with limited mobility, the Xbox Adaptive Joystick helps make gaming more accessible for however you play."
"Connect to the Xbox Adaptive Controller for a full adaptive setup. Plug directly into your console or PC and link with an Xbox controller for full controller functionality. Fine tune your gaming setup until it’s perfect for you because when everyone plays, we all win."
If you're curious and want to know more, there's a big page on the official Xbox Website that's dedicated to the Xbox Adaptive Joystick, complete with support sections where you can delve into the nitty-gritty of things like compatibility.
Better yet, the Xbox Design Lab is also offering the ability to design your own Adaptive Thumbstick Toppers to customise the device to your liking, although this is just a do-it-yourself service that requires access to a 3D printer.
We'll leave you with a few screenshots of the Xbox Adaptive Joystick courtesy of Microsoft: