00_Readme.md

Place this in functions.php of your theme or somewhere else it can be called. This adds a link to the WP Admin bar that will deep link you to edit a particular section of the theme customizer in the admin backend.

You can read more about this here

The trick is to link to /customize.php?autofocus[section]={your_section_here}. Some section names in default WP are:

• title_tagline (For Site Identity)
• colors (For colors)
• background_image (For Background Image)

So if you wanted to deep link to editing the site identity it would look like:

'href' => get_admin_url() . '/customize.php?autofocus[section]=title_tagline'

01_add_link.php

<?php
// The function name here as the second argument can be whatever you want, it just has to match the function name on line 5
add_action( 'admin_bar_menu', 'social_media_links', 900 );
// This function name must match the second argument to add_action() up above, change it to your liking
function social_media_links( $wp_admin_bar )
{
  // If you don't include the "get_admin_url()" call then WP will yell at you about no input file specified when it redirects
  // The autofocus[section]= is what "deep links" you to that customizer section
  // In this case I'm using a custom section that I've added via WP_Customize_Control
	$args = array(
		'id'     => 'social_media',
		'title'	 => 'Edit Social Media Links',
    		'href'   => get_admin_url() . '/customize.php?autofocus[section]=deadeye_social_media',
		'meta'   => array( 'class' => 'first-toolbar-group' ),
	);
	$wp_admin_bar->add_node( $args );
}