Another way you can do is simulate a creation of a new Compute Instance, and down the bottom you have the option of seeing a command line version, which generally has all the options you can pick from the Console in written text, and you can adjust as see fit. Bit messy i know, but at least you can visualise all the options.
You can se how to pass scopes in the console here, with –scopes=[SCOPE]
https://cloud.google.com/sdk/gcloud/reference/compute/instances/create#–scopes
Another way you can do is simulate a creation of a new Compute Instance, and down the bottom you have the option of seeing a command line version, which generally has all the options you can pick from the Console in written text, and you can adjust as see fit. Bit messy i know, but at least you can visualise all the options.