You may not.
Homebrew can only really launch actual apps. System apps, games, stuff like that.
The things at the top of your home menu, however (Game Notes, Friends list, Notifications, Web Browser and MiiVerse), are Applets, which behave differently to normal apps. They run on the home menu alongside any app you may be running.
Homebrew gives us userland access, which is, anything a regular game or app can access. That is because it runs as a game. Games can't launch applets on their own, you have to launch them from the home menu, so we can't run them from HBL.
In fact a few of these applets show up on N3DS in HBL when trying to use region free launcher (or at least they show up in title launcher on masher's launcher), but attempting to select them to run them only blackscreens.