Primary slug in WordPress CMS permalink while multiple categories.

Here I have uploaded screenshot what I have worked for manage WordPress CMS Permalink.
Sometimes single post assigned to multiple categories in WordPress so permalink of that post load best on category.
I have added demo that how to change category slug in permalink.

<?php
if ( ! defined( 'ABSPATH' ) ) {
  exit; // Exit if accessed directly
}
/**
 * Plugin Name: WP Get POST
 * Plugin URI:  http://punit.info
 * Description: Ability to get post from primary category
 * Version:     1.0.0
 * Author:      Punit
 * Author URI:  http://punit.info/
 * Text Domain: wpwgp
 * Domain Path: /languages
 */

/**
 * Class : Wp_Get_Post
 *
 * @since  1.0.0
 * @access public
 */
if ( ! class_exists( 'Wp_Get_Post' ) ) :
  class Wp_Get_Post {

    /**
     * Plugin directory path.
     *
     * @since  1.0.0
     * @access public
     * @var    string
     */
    public $dir_path = '';

    /**
     * Plugin directory URI.
     *
     * @since  1.0.0
     * @access public
     * @var    string
     */
    public $dir_uri = '';

    /**
     * Plugin admin directory path.
     *
     * @since  1.0.0
     * @access public
     * @var    string
     */
    public $admin_dir = '';

    /**
     * Plugin includes directory path.
     *
     * @since  1.0.0
     * @access public
     * @var    string
     */
    public $inc_dir = '';

    /**
     * Plugin CSS directory URI.
     *
     * @since  1.0.0
     * @access public
     * @var    string
     */
    public $css_uri = '';

    /**
     * Plugin JS directory URI.
     *
     * @since  1.0.0
     * @access public
     * @var    string
     */
    public $js_uri = '';

    /**
     * Returns the instance.
     *
     * @since  1.0.0
     * @access public
     * @return object
     */
    public static function get_instance() {

      static $instance = null;

      if ( is_null( $instance ) ) {
        $instance = new Wp_Get_Post();
        $instance->setup();
        $instance->includes();
      }

      return $instance;
    }

    /**
     * Sets up globals.
     *
     * @since  1.0.0
     * @access private
     * @return void
     */
    private function setup() {

      // Main plugin directory path and URI.
      $this->dir_path = trailingslashit( plugin_dir_path( __FILE__ ) );
      $this->dir_uri  = trailingslashit( plugin_dir_url( __FILE__ ) );

      // Plugin directory paths.
      $this->inc_dir   = trailingslashit( $this->dir_path . 'inc' );
      $this->admin_dir = trailingslashit( $this->dir_path . 'admin' );

      // Plugin Version
      $this->version = '1.0.0';
    }

    /**
     * Loads the translation files.
     *
     * @since  1.0.0
     * @access public
     * @return void
     */
    public function i18n() {
      load_plugin_textdomain( 'wpwgp', false, trailingslashit( dirname( plugin_basename( __FILE__ ) ) ) . 'languages' );
    }

    /**
     * Loads files needed by the plugin.
     *
     * @since  1.0.0
     * @access private
     * @return void
     */
    private function includes() {

      // Load admin files.
      if ( is_admin() ) {

        // General admin functions.
        if ( file_exists( $this->admin_dir . 'class-get-post.php' ) ) {
          require_once $this->admin_dir . 'class-get-post.php';
          $admin_instance = new Admin_Get_Post();// Call Default functions
          $admin_instance->admin_hook();
        }
      }
      // Post link category
      add_filter( 'post_link_category', array( $this, 'post_link_category' ), 10, 3 );

    }

    /**
     * Filters post_link_category to change the category to the chosen category by the user
     *
     * @param stdClass $category The category that is now used for the post link.
     * @param array    $categories This parameter is not used.
     * @param WP_Post  $post The post in question.
     *
     * @return array|null|object|WP_Error The category we want to use for the post link.
     */
    public function post_link_category( $category, $categories = null, $post = null ) {
      $post             = get_post( $post );
      $primary_category = get_post_meta( $post->ID, '_wgp_primary_' . $post->post_type, true );

      if ( empty( $primary_category ) ) {
        return $category;
      }

      if ( false !== $primary_category && $primary_category !== $category->cat_ID ) {
        $category = get_category( $primary_category );
      }

      return $category;
    }
  }
endif;

/**
 * Gets the instance of the `Wp_Get_Post` class.  This function is useful for quickly grabbing data
 * used throughout the plugin.
 *
 * @since  1.0.0
 * @access public
 * @return object
 */
function wp_get_post() {
  return Wp_Get_Post::get_instance();
}

// Let's roll!
wp_get_post();

By using this plugin user can change category URL in permalink based on multiple category.