The built-in options are limited--the only thing is the table that the http://YourHubIP/hub/zigbee/getChildAndRouteInfo URL will spit out. You won't (necessarily) see all devices here, just ones in either direct range of the hub or close enough (one "hop"/repeater, I think?) that they show up.
Some community members use an Xbee to map their network, act as a (good) router, or both. There is a thread with lots of information: Everything Xbee. The XCTU software you need to "program" the module can also build a map of the network, whether the Xbee is added as a router (which you'd do for Hubitat) or acting as a coordinator. DeCONZ is another piece of software I know of that can map Zigbee networks, but it only works with a ConBee (or RaspBee) and I don't think there's a way to join those as routers/repeaters, only coordinators, so I don't think those would work with Hubitat.
But for the most part, Zigbee (and Z-Wave) are good enough about figuring out routes and there's usually not much reason to look into this kind of thing unless you're having problems--besides curiosity. 
