<mat-menu>
is a floating panel containing list of options.
Menus support displaying
<mat-icon>
elements before the menu item text.
Material supports the ability for an mat-menu-item to open a sub-menu. To do so, you have to define your root menu and sub-menus, in addition to setting the [matMenuTriggerFor] on the mat-menu-item that should trigger the sub-menu
[overlapTrigger]="false"
attribute.