New to my SDS 200, however when I am away from my UT this is a work around that is working for me.
Set up a custom search, for me I use 7 for 700MHZ and 8 for 800MHZ.
Create a new P25 trunking system. I called mine P25 Wild. Under system options be sure to enable TG search. For the Site rename it wild and put any frequency as a placeholder. Department put any one TG as placeholder.
Then back to a custom search, when the scan stops on a valid system ID and top right says data this is a valid control channel.
Make a note of frequency and enter that into the wild system site frequency.
You will then enable that system, the radio will display all the parameters of the system including RFSS, Site, NAC and sys id.
So not exactly neighbors, but might get you in the neighborhood of finding new sites on a system.