In order to restore data using the graphSON snapshot, here are the steps to follow
Check the snapshots folder in the graphadmin pod running in your namespace:
kubectl exec -it $(kubectl get pods -lapp=aai-graphadmin -n onap | grep -v 'NAME' | awk '{ print $1; }') -n onap -- ls -ltr /opt/app/aai-graphadmin/logs/data/dataSnapshots/