Probably best to try all other approaches to isolate them via os type, location, model, name fragments or something else if possible, but you can eventually get there with some numeric regexing probably.
dynamic group. It is mostly Ubiquiti AirOS devices, for some reason LibreNMS does not think that they match the query but difficult to see why as “Resolved IP” for every host always matches.
Maybe those devices don’t have anything in the ipv4_addresses table.
I don’t know exactly how addresses end up in there or how they are then associated to devices, but just so happens all mine do - a mix of random Cisco, Moxa, whitelabel APs etc.
Hopefully someone else knows a bit more about those internals.