The items of a Context Menu widget can start their own submenus, which allows creating multi-level structures. To browse submenus you need to either hover or click Context Menu items, which is tuned in the widget configuration.
Hover menu items to see their submenus
Attached to a widget
The Context menu widget can be used with any other Webix widget. Adding a context menu to an existing widget doesn’t require much effort. All you have to do is add an extra property to the widget's configuration. After initializing the context menu you can use its API to link it to the previously created widget.
Right click to show context menu