Page Selector in Customizer

gistfile1.php

/**
 * Add page selector to the customizer.
 *
 * @since Theme 1.0.0
 *
 * @param WP_Customize_Manager $wp_customize Customizer object.
 */
function prefix_customize_register( $wp_customize ) {

	$wp_customize->add_section( 'showcase' , array(
    		'title'      => __( 'Showcase', 'textdomain' ),
		'priority'   => 30,
	) );

	for ( $count = 1; $count <= 4; $count++ ) {

		// Add color scheme setting and control.
		$wp_customize->add_setting( 'showcase-page-' . $count, array(
			'default'           => '',
			'sanitize_callback' => 'absint'
		) );

		$wp_customize->add_control( 'showcase-page-' . $count, array(
			'label'    => __( 'Select Page', 'textdomain' ),
			'section'  => 'showcase',
			'type'     => 'dropdown-pages'
		) );

	}

}
add_action( 'customize_register', 'prefix_customize_register' );