The Channel button is for direct entry. While it will work for a TG as long as you're on that system, it will not work for conventional frequencies or when you are scanning a different trunked system (it will cause a hold mode on that TG on the wrong system).
The Menu button will always work and is the method mentioned in the manual.
If your talking number tags to go directly to a channel to monitor it that is in a fav list you have...
It's in the manual....
Press Channel to hold on any channel.
Enter the Favorites number tag, .no, the System number tag, .no, then the Channel number tag and press Channel.
Press Channel to resume.
Examples:
2.5.6 to go to Channel 6 in System 5 in Favorites List 2.
1.10.36 to go to Channel 36 in System 10 in Favorites List 1.
.10.36 to go to Channel 36 in System 10 in current Favorites List.
..36 to go to Channel 36 in current System.
2. to go to Favorites List 2 (1st channel in 1st department in 1st system).
2.5. to go to System 5 in Favorites List 2 (1st channel in 1st department).