GameMenuBuilder

Looking at some of the Epic sample projects it looks like they use functionality from something called GameMenuBuilder that comes with the engine source code. This includes classes like FGameMenuPage and FGameMenuItem and seems to help with creating menus and linking submenus together.

The only problem is it looks like it was meant to work with Slate Widget and not UMG Widgets. Is there any equivalent system for UMG Widgets which would provide this functionality?

It seems like most Epic examples use Slate with GameMenuBuilder to build their menu systems. Are there any examples using UMG for creating a game menu system with submenus?

The manual way that I have seen is (OnClicked - Remove from Parent - Create New Widget - Add to Viewport) but there is no system for adding or navigating submenus like with GameMenuBuilder.

Call me a digger^

GameMenuBuilder is used for paged menus or setting screens and seems to be like a lazy way to make simple UI in C++.
Along with FGameMenuPage - as name suggest
FGameMenuItem - option in menu page.

Guess Slate just killed it.