If you haven't already, download
this from Garmin. Makes life easier.
In your "Custom POI" folder create sub folders and name then "Tim's", "Beer Store", "Booze", "AA Meetings

", etc, etc.... This should work.
Now when you hit Custom POI the subcategories will show up instead of 1 long list
Some units have a bug, You have to have at least 2 sub folders with at least 2 POI's each B/4 they will show up on the screen, but it sounds like you have that covered.