Custom menus can be constructed using a composable approach by combining the menu and menu toggle components in unique ways. To handle basic keyboard inputs, dropdown, select, or
<MenuContainer> components may be used in combination with menu components.
Additionally, menu components may be connected to each other manually through our undocumented internal popper.js wrapper component called Popper.
Tree view menu
When rendering a menu-like element that does not contain
<MenuItem> components, panel allows more flexible control and customization.
The flyout will automatically position to the left or top if it would otherwise go outside the window. The menu must be placed in a container outside the main content like Popper, popover or tooltip, since it may go over the side nav.
View source on GitHub