How to Create Custom taxanomy

WordPress taxonomies are used as a way to group posts and custom post types together.
You can use custom taxonomies to create custom groups and bring them under one umbrella.

DEFAULT TAXONOMIES IN WORDPRESS

1. Categories (hierarchal),
2. Tags (multifaceted),

CREATE A CUSTOM TAXONOMY

In WordPress, you can create (or “register”) a new taxonomy by using the register_taxonomy() function. Each taxonomy option is documented in detail in the WordPress Codex.

A Practical Example: Content By Location

A business that operates in multiple locations could benefit from organizing its content by location to allow visitors to browse news in their locality. A large news organization could organize its content by world region (Africa, Asia, Europe, Latin America, Middle East, US & Canada), as the BBC does in its “World” section.

Manually Creating Custom Taxonomies

Add the following code in your theme’s functions.php

/**
 * Add custom taxonomies
 *
 * Additional custom taxonomies can be defined here
 * http://codex.wordpress.org/Function_Reference/register_taxonomy
 */
function add_custom_taxonomies() {
  // Add new "Locations" taxonomy to Posts 
   register_taxonomy('location', 'post', array(
    // Hierarchical taxonomy (like categories)
    'hierarchical' => true,
    // This array of options controls the labels displayed in the WordPress Admin UI
    'labels' => array(
      'name' => _x( 'Locations', 'taxonomy general name' ),
      'singular_name' => _x( 'Location', 'taxonomy singular name' ),
      'search_items' =>  __( 'Search Locations' ),
      'all_items' => __( 'All Locations' ),
      'parent_item' => __( 'Parent Location' ),
      'parent_item_colon' => __( 'Parent Location:' ),
      'edit_item' => __( 'Edit Location' ),
      'update_item' => __( 'Update Location' ),
      'add_new_item' => __( 'Add New Location' ),
      'new_item_name' => __( 'New Location Name' ),
      'menu_name' => __( 'Locations' ),
    ),
    'show_in_rest'=> true,  // if not show taxanomy on your post
    // Control the slugs used for this taxonomy
    'rewrite' => array(
      'slug' => 'locations', // This controls the base slug that will display before each term
      'with_front' => false, // Don't display the category base before "/locations/"
      'hierarchical' => true // This will allow URL's like "/locations/boston/cambridge/"
    ),
  ));
}
add_action( 'init', 'add_custom_taxonomies', 0 );

After adding this to your theme’s functions.php file, you should see a new taxonomy under the “Posts” menu in the admin sidebar. It works just like categories but is separate and independent.

After adding a few terms to your new taxonomy, you can begin to organize the content in your posts by location. A new “Locations” box will appear to the right of your posts in the WordPress admin area. Use this the way you would categorize.

Let’s use this “location” taxonomy as a jumping-off point to learn more about working with taxonomy functions and content.