You just need to setup NodeBB on two different ports, and have nginx serve them to your appropriate subdomain. What's your current setup like?
NodeBB and Jabber
Not sure if this has been covered already but I wasn't able to find it on the forums. Does NodeBB have Jabber integration?
@Tanner no, but I don't know what Jabber does or how it would integrate. Please explain.
@a_5mith Some other BB systems will send notifications over the XMPP Chat protocol (like Old Google Talk). I'm not sure how useful that is in this day and age though.
Given that I recently added Push Notification support via my Pushbullet plugin, I'd say Jabber/XMPP support could also be done via a plugin as well