I will flag this post for the developer, but I’m not sure if this is at all possible.
The current “Uploaded to post” option uses built in functionality of WP to accomplish. When an image is uploaded while editing a post WP marks the uploaded file as an “attachment” to the post. So ACF is just using this to detect what images have been uploaded to the post. There is nothing that exists in WP to determine what post type or what field a file has been uploaded to.
