If you connect to a cluster through a tribe node, and you want to monitor the tribe node, then you will need to install X-Pack on that node as well.

With this configuration, the tribe node is included in the node count displayed in the Monitoring UI, but is not included in the node list because it does not export any data to the monitoring cluster.

To include the tribe node in the monitoring data, enable Monitoring data collection at the tribe level:

node.name: my-tribe-node1

tribe:
  on_conflict: prefer_cluster1
  c1:
    cluster.name: cluster1
    discovery.zen.ping.unicast.hosts: [ "cluster1-node1:9300", "cluster1-node2:9300", "cluster1-node2:9300" ]
    xpack.monitoring.enabled: true 
  c2:
    cluster.name: cluster2
    discovery.zen.ping.unicast.hosts: [ "cluster2-node3:9300", "cluster2-node3:9300", "cluster2-node3:9300" ]
    xpack.monitoring: 
      enabled: true
      exporters:
        id1:
          type: http
          host: [ "monitoring-cluster:9200" ]

When you enable data collection from the tribe node, it is included in both the node count and node list.