Enhancing WordPress Custom Menus for Navigation

Custom navigation menus are an amazing WordPress feature that allows admin users to add any list of links anywhere into the site. They can be links to internal resources, like posts, pages and archives, as well as links to external resources, like your social profiles pages. WordPress reserves a specific admin page to custom navigation menus. In this page the admin user can create menus, arrange items and set properties which affect the way they appear in the front-end. WordPress Appearance Menus Screen
That being said, the main questions behind this post is: “Can we extend the built-in functionalities of the Menus Screen?”
Of course we can. So I will dive deep into the topic, and I will dissect sections and objects that allow to add and manage menus and their items. But it won’t be just a description of the screen. I will show you how to add custom items to the accordion menu placed in the left sidebar.
These custom boxes will show additional lists of links to choose from when building custom navigation menus. More specifically, I will show you how to add a box containing links to the site authors’ archives.
Let’s start diving into building a WordPress
Source: https://managewp.org/articles/13814/enhancing-wordpress-custom-menus-for-navigation

source https://williechiu40.wordpress.com/2016/11/10/enhancing-wordpress-custom-menus-for-navigation/