I just ordered the SDS100 and I'm trying to setup Sentinel in anticipation of my scanner. I watched the SM youtube video and I'm trying to add favorites by doing the same thing, but I'm not getting the same results.
I navigate to: USA>Texas>Harris>Statewide>Texas Wide Area Radio Network.
From there I find a specific TG; example: Air Medical. When I either add the individual channel, or the entire Air Medical group to my favorites, it adds the entire TxWARN to my favorites and not the specific TG.
Why?
Expand the TxWARN entry so that you can see all of the various departments, and sites, down below the top entry.
Find what you want to append to a Favorites list and highlight it
Right Click on your highlighted and select Append to Favorites list

Sentinel will then show the list of Favorites that you already have. If creating a new list, select that option at the bottom of the pop-up.
Sentinel will ask you to name the new list. Either create a new named list, or choose to append to an existing list.
Once you proceed, you'll have a list with the talkgroup you selected, which will be in a folder (representing the department), along with all of the sites.
From this point, you can leave the sites, but also enable location control, which will disable scanning the sites well out of range.
Or, you can trim out the sites you
do not want.
Thats just how it works - first, you need to have the system in your list, otherwise itll add the whole thing.
Add the whole thing, then delete the ones you dont want - you can press "CTRL + A" to select all, then while holding CTRL, click the one you want and it will "unhighlight" and you can then right-click and delete them all.
If you use this method, be sure that you do not remove the sites in your area, or the Department that you appended.
You can also preserve the specifc sites you want to keep, but then select the ones you don't. Holding down the Shift key, and clicking the first, and last, site in a contiguous list, you can remove a number of them at the same time. For sites that are not next to each other, hold down the control key and select the ones to remove. Once you have a list of sites to remove, do that either by <Right clicking> on one of the selected sites, then choose 'Remove from Favorites list' from the pop-up menu, or simply hit the Delete key. Sentinel will ask you to confirm if you want to remove those.
While the names of some of the sites will be a city or other area familiar to you, not all of them will be. So, pull up the system in the database.
Then, click on the
Control above the column of counties for the sites. That will re-sort the sites in alphabetical order, by county name.

That makes it easier for you to identify the ones you do, or do not, want.
Also, once you have cleared the excess sites, you can now append other talkgroups or departments to your list. As long as you do not change the system's name, it will only append selected departments or talkgroups. It won't flood all of discarded sites back into your list.