This extension contains a custom node for ComfyUI. The node, called 'Bounding Box Crop', is designed to compute the top-left coordinates of a cropped bounding box based on input coordinates and dimensions of the final cropped image. It does so computing the center of the cropping area and then computing where the top-left coordinates would be.
https://github.com/alessandrozonta/ComfyUI-CenterNode
git clone https://github.com/alessandrozonta/ComfyUI-CenterNode
comfy node install comfyui-centernode