How to multiple hosts??

I have three server.
And one server is pm2-web server. monitoring server.
the others server is pm2 program server,

monitoring server is add to the others server(host, rpc,events) in config.json

so not disconnecting.

I hope external server add in my pm2-web monitoring server.

How to add multiple hosts??
and how to configuration??

Help Me!!!! T.T