The second method is a bit more involved, but will allow you to see and control the TG ID's, as well as see User ID's.
This method involves programming a new One Frequency Trunk (OFT) system for DMR. You set it up more or less like you'd setup a trunked system, however the frequencies are actually conventional DMR. Contrary to it being called One Frequency Trunk, you can actually add more than one frequency to the system. In this case, you could add all three of their frequencies and have it scan them almost like a trunked system without a control channel, where it will simply look at all three frequencies and stop on any DMR activity.
You can program talkgroups with that method, allowing you to give them aliases and/or lock talkgroups out. So for example if you only want to listen to Fire Operations, you can program and then lock out TG 14350000 so that the scanner won't stop on PD Dispatch activity on 154.785