What would I need to do to route traffic for example.org to a particular host on my LAN?
well does example.org resolve to your public IP on the public internet? If so then just forward the ports you want to be served up by the machine behind pfsense.
if your talking about example.com going to machine 1 behind pfsense, while otherdomain.com going to different machine then you need to use a reverse proxy if you don't have more than 1 public IP.
All I really want is the equivalent of a hosts file which contains something like
but have this on pfSense rather than every system on the lan. I am not interested in accessing this system from outside.
It's probably pretty straightforward but I'm not sure how to go about it. I'm no pfSense expert, just a user…
so you want users using pfsense as their dns to resolve host.example.org to 192.168.1.99 that is a simple host override in either the forwarder or resolver depending on which one your using.
if you want example.org you could do that to with example being the host and org being the domain - see attached screenshot of my resolver overrides, and then my queries for them to pfsense.
The higher response times are because I am via vpn connection to my home network, that has to bounce off proxy in texas, then back to chicagoland while I am in chicagoland.