This cannot be mounted to a chair, but you could mount it to a floor or baseplate of some sort to anchor it. That would allow you to use it in a ground blind for your Crossbow. A better option might be their chair that already has it built in: https://www.opticsplanet.com/caldwell-deadshot-chairpod.html
Please also refer to the other answer under this question for a users experience with the product in this circumstance.
It CAN. In response to mounting the treepod to a wheelchair. Not to dispute but to help those in need and responding as one who has experience and knows it is possible. Although it is not designed or marketed as such; it can be mounted to a wheelchair if there is a flat plat foot rest on the chair. May have to drill some holes, but that's no big task. I have mounted and used the treepod on electric power chairs and manual chairs by mounting to the foot rest plates. Also other mounting options are possible with a little fabrication; brackets can be made to bolt to frame rails and seat frames. Caldwell Deadshot Treepod is a very good accessory for handicap rifle shooters. Almost a must have for balancing the firearm and shooting accuracy.