Kibana showing data from two ES instances

Hello, I would like to have two ES instances in different machines, but a Kibana interface able to access both of them. Something like this:

How could I do it?
My first idea is to create a cluster with two nodes (1 node for ES instance 1 and the other one for ES instance 2) , but how could I create a cluster with nodes from diferent machines? which parameter should I change from elasticsearch.yml?


The needs to be the same, then change as per here.