What is the easiest method in locating your GMB listings CID or Place ID?
The easiest method is by downloading an extension called GatherUp. It’s a free extension and makes obtaining your CID and Place ID extremely easy. Once you downloaded the extension, navigate to any knowledge graph or Google Map listing and click the extension. You will be given 2 links. The 1st is the Google Maps URL, which contains the CID. The 2nd is the Review URL which contains the Place ID.
Google Maps URL: https://www.google.com/maps?cid=15126324006846679370
Google Write a Review URL: https://search.google.com/local/writereview?placeid=ChIJh-nmHeTm5okRSkmPoYp_69E
Storing this information can be useful, depending on what you are trying to accomplish.