Configuring Single Kibana server for multiple Elastic search clusters

This can be accomplished with a Tribe node.

You can find more information about configuring a tribe node here: https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-tribe.html

The tribe node will allow you to query data from both clusters.

In your kibana.yml:

elasticsearch.url: http://my_kibana_cluster:9200
elasticsearch.tribe.url: http://my_tribe_node:9200

http://my_kibana_cluster:9200 will need to be a non-tribe cluster which will be used to persist the .kibana index.

Here is additional information on using tribe with Kibana: https://www.elastic.co/guide/en/kibana/current/tribe.html