I find that by saving the json from a web api as a json file to my desktop, then uploading it to Firebase, you can find the path easily. I noticed that when working with the wordpress rest api, the data is clumped together. By uploading to Firebase just to view, you can find the path very easy. Just make a test project and try it out!
(edit)
I forgot to mention, this doesn’t have to be a web api of course. Just upload the json file to Firebase and you are good to go!