Would someone be able to help me with editing a photograph in Camera Raw, whilst in Photoshop. Then, at a later time, reopening the photograph in Camera Raw, whilst in Photoshop. I am unable to find it. I do have the latest Photoshop CC 2018 installed and all the appropriate plug-ins. Thank you.
If it is a raw file then it will open ACR and after adjusting , will appear in the layer stack as a smart object. Double click the smart object and the raw file will open again in ACR so you can make further adjustments
If it is not a raw file - it will open directly as a smart object and you can apply the Filter >Camera raw to that smart object. This time to readjust - click on the Camera Raw filter adjustment.