gcloud auth login [SERVICE_PROJECT_ADMIN]
gcloud beta compute networks subnets list-usable --project [HOST_PROJECT_ID]
gcloud compute instances create [INSTANCE_NAME] \ --project [SERVICE_PROJECT_ID] \ --subnet projects/[HOST_PROJECT_ID]/regions/[REGION]/subnetworks/[SUBNET] \ --zone [ZONE]More details are available here. In addition, if you have any feedback for improvement to this, feel free to submit a feature request using GCP public issue tracker.