Second Submenu Not Rendering

[UAScotttJaxon]

Problem/Motivation

Secondary submenu items are not showing up.

Describe the bug

If more than 2 menu items in same drop down have submenu items the top most menu item shows when bottom most menu item is clicked. Residency clicked shows 3 submenu items:

Fellowship when clicked shows Residencies 3 submenu items:

To Reproduce

1. Go to a menu make it a drop down and add 2 sub-menu items under different drop down menu items.
2. Click on down arrow for top menu item to show submenu.
3. Click on down arrow for bottom menu item to show submenu.
4. See that both show the same submenu w/ Top submenu items being dominant
5. Make web browser mobile view
6. Open mobile view main menu
7. Click down arrow to open both submenus
8. See that in mobile view both submenu items show

Proposed resolution

Make main menu behave like mobile menu

Expected behavior

Second submenu should show those submenu items; not submenu items of First submenu

Screenshots

Mobile menu shows both submenu items:

Top drop down is dominant:

Additional context

https://www.drupal.org/forum/support/theme-development/2016-04-01/submenu-not-showing

https://www.drupal.org/forum/support/module-development-and-code-questions/2019-08-03/menu-item-children-not-rendered-in

[bberndt-uaz]

@UAScotttJaxon Thanks for opening this issue. The problem where only the first submenu is displayed seems to be a limitation of Bootstrap dropdowns, since they do not support nesting by default. We are currently looking to resolve this as part of a larger initiative to revise navigation in Quickstart. See this Google presentation for more details about this initiative. @danahertzberg will be adding GitHub issues for the navigation updates soon.