$wp_customize->add_section(
		'smu_bio', array(
			'title' => __('Bio Section', 'smu'),
			'priority' => 70,
		));

	// Link

	$wp_customize->add_setting('smu_bio_link', array(
		// note - works with or without capability & type set
		'capability' => 'edit_theme_options',
		'type' => 'option',
		// note - need to add sanitize callback
	));

	$wp_customize->add_control('smu_bio_link', array(
		'label' => __('Link', 'smu'),
		'section' => 'smu_bio',
		'type' => 'dropdown-pages',
		'settings' => 'smu_bio_link',
	)); // end link


https://kovshenin.com/2014/social-menus-in-wordpress-themes/