Sample plugin to show adding a new WooCommerce settings tab

sample-wc-new-settings-tab.php

<?php
/**
 * Plugin Name: Sample WooComm Settings Plugin
 * Plugin URI: http://www.skyverge.com/
 * Description: A sample of a new working settings tab
 * Author: SkyVerge
 * Author URI: http://www.skyverge.com/
 * Version: 1.0
 * Text Domain: my-textdomain
 * Domain Path: /i18n/languages/
 *
 * @package   My-Plugin/Admin
 * @author    SkyVerge
 * @category  Admin
 * @copyright Copyright (c) 2016, SkyVerge, Inc
 * @license   http://www.gnu.org/licenses/gpl-3.0.html GNU General Public License v3.0
 */


if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly


if ( ! class_exists( 'WC_Settings_MyPlugin' ) ) :


function my_plugin_add_settings() {

	/**
	 * Settings class
	 *
	 * @since 1.0.0
	 */
	class WC_Settings_MyPlugin extends WC_Settings_Page {

		
		/**
		 * Setup settings class
		 *
		 * @since  1.0
		 */
		public function __construct() {
		
			$this->id    = 'myplugin';
			$this->label = __( 'PluginName', 'my-textdomain' );
			
			add_filter( 'woocommerce_settings_tabs_array',        array( $this, 'add_settings_page' ), 20 );
			add_action( 'woocommerce_settings_' . $this->id,      array( $this, 'output' ) );
			add_action( 'woocommerce_settings_save_' . $this->id, array( $this, 'save' ) );
			add_action( 'woocommerce_sections_' . $this->id,      array( $this, 'output_sections' ) );

		}
		
		
		/**
		 * Get sections
		 *
		 * @return array
		 */
		public function get_sections() {
		
			$sections = array(
				''         => __( 'Section 1', 'my-textdomain' ),
				'second' => __( 'Section 2', 'my-textdomain' )
			);
			
			return apply_filters( 'woocommerce_get_sections_' . $this->id, $sections );
		}
		

		/**
		 * Get settings array
		 *
		 * @since 1.0.0
		 * @param string $current_section Optional. Defaults to empty string.
		 * @return array Array of settings
		 */
		public function get_settings( $current_section = '' ) {
		
			if ( 'second' == $current_section ) {
			
				/**
				 * Filter Plugin Section 2 Settings
				 *
				 * @since 1.0.0
				 * @param array $settings Array of the plugin settings
				 */
				$settings = apply_filters( 'myplugin_section2_settings', array(
				
					array(
						'name' => __( 'Group 1', 'my-textdomain' ),
						'type' => 'title',
						'desc' => '',
						'id'   => 'myplugin_group1_options',
					),
					
					array(
						'type'     => 'checkbox',
						'id'       => 'myplugin_checkbox_1',
						'name'     => __( 'Do a thing?', 'my-textdomain' ),
						'desc'     => __( 'Enable to do something', 'my-textdomain' ),
						'default'  => 'no',
					),
				
					array(
						'type' => 'sectionend',
						'id'   => 'myplugin_group1_options'
					),
					
					array(
						'name' => __( 'Group 2', 'my-textdomain' ),
						'type' => 'title',
						'desc' => '',
						'id'   => 'myplugin_group2_options',
					),
					
					array(
						'type'     => 'select',
						'id'       => 'myplugin_select_1',
						'name'     => __( 'What should happen?', 'my-textdomain' ),
						'options'  => array(
							'something' => __( 'Something', 'my-textdomain' ),
							'nothing' 	=> __( 'Nothing', 'my-textdomain' ),
							'idk'    	=> __( 'IDK', 'my-textdomain' ),
						),
						'class'    => 'wc-enhanced-select',
						'desc_tip' => __( 'Don\'t ask me!', 'my-textdomain' ),
						'default'  => 'idk',
					),
				
					array(
						'type' => 'sectionend',
						'id'   => 'myplugin_group2_options'
					),
					
				) );
				
			} else {
				
				/**
				 * Filter Plugin Section 1 Settings
				 *
				 * @since 1.0.0
				 * @param array $settings Array of the plugin settings
				 */
				$settings = apply_filters( 'myplugin_section1_settings', array(
				
					array(
						'name' => __( 'Important Stuff', 'my-textdomain' ),
						'type' => 'title',
						'desc' => '',
						'id'   => 'myplugin_important_options',
					),
					
					array(
						'type'     => 'select',
						'id'       => 'myplugin_select_1',
						'name'     => __( 'Choose your favorite', 'my-textdomain' ),
						'options'  => array(
							'vanilla'        => __( 'Vanilla', 'my-textdomain' ),
							'chocolate'		 => __( 'Chocolate', 'my-textdomain' ),
							'strawberry'     => __( 'Strawberry', 'my-textdomain' ),
						),
						'class'    => 'wc-enhanced-select',
						'desc_tip' => __( 'Be honest!', 'my-textdomain' ),
						'default'  => 'vanilla',
					),
				
					array(
						'type' => 'sectionend',
						'id'   => 'myplugin_important_options'
					),
					
				) );
				
			}
			
			/**
			 * Filter MyPlugin Settings
			 *
			 * @since 1.0.0
			 * @param array $settings Array of the plugin settings
			 */
			return apply_filters( 'woocommerce_get_settings_' . $this->id, $settings, $current_section );
			
		}
		
		
		/**
		 * Output the settings
		 *
		 * @since 1.0
		 */
		public function output() {
		
			global $current_section;
			
			$settings = $this->get_settings( $current_section );
			WC_Admin_Settings::output_fields( $settings );
		}
		
		
		/**
	 	 * Save settings
	 	 *
	 	 * @since 1.0
		 */
		public function save() {
		
			global $current_section;
			
			$settings = $this->get_settings( $current_section );
			WC_Admin_Settings::save_fields( $settings );
		}

	}
	
	return new WC_Settings_MyPlugin();

}
add_filter( 'woocommerce_get_settings_pages', 'my_plugin_add_settings', 15 );

endif;

Line #46 change add_settings_page to get_sections