Cascading Menu

[poco2013]

As a Newbie, I'm trying to create a sub-menu on the third level.
I'm OK with the first two levels, but can't figure out how to attach a sub menu to item 1A-A to create the third level per the attached image?

[ReignBough]

General wrote:
Cascading/hierarchic menu items

Use this item type if an Add-On needs more than one or two commands, or to organize the commands into a logical order. The number of items within the submenu is limited by OS constraints only. A single level of submenus is available only. Items of the submenus cannot be hierarchic.