How to use Bucket Script


I’m just trying to figure out how to use the Metric Bucket script for Elasticsearch (Grafana 6.0.2, Elasticsearch 5.2.2).
I followed the link of the “Whats new” documentation and read the Elasticsearch documentation.

Special I can’t get any further with the field ‘select metric’.
Everything I enter is discarded immediately and does not end up in the query “buckets_path”.

I have tried the following input:
“sum”:{“field”: “”}

Can someone give me a simple input to get the stone to roll?

Thank you very much.
Jan L.

Ok, I got it now.
‘select metric’ field will get some drop-down values, after adding additional Metric fields to the query.