How do I rename an available field? So for example we pull logs from GCP and use a json filter before outputting it to elasticsearch. The message field shows an event named "bytes_sent" but in Kibana under Available Fields it shows as jsonPayload.bytes_sent. Is there a way to strip the jsaonPayload. so it just shows as bytes_sent? I have tried rename and mutate filters within logstash but they dont appear to do anything.....provided this is even the right thing to do.