Volumes are used to turn post processing on/off, not affect just an area of the screen. If what you are asking to do is have an area around the chair in focus and everything out of focus, you can use depth of field to achieve that. However that is focal point and range controlled so if the player moves, the DoF moves with their camera
Ok, I’ll try to be more specific. The effect that I am trying to achieve is to have an object that the player is looking at to be in focus. With all other areas of the screen blurred. Like having a focal point instead of a distance, with the transition region being more like a radius.