I created a custom post type called members:

// Custom post types

function members_post_type()
{
    $args = array(
        'labels' => array(
            'name' => 'Members',
            'singular_name' => 'Member',
            'all_items' => 'All members'
        ),
        // 'hierarchical' => true,
        'public' => true,
        'has_archive' => true,
        'supports' => array('title', 'editor' , 'thumbnail'),
        'menu_icon' => 'dashicons-groups'
    );
    register_post_type('members', $args);
}

add_action('init', 'members_post_type');

function members_taxonomys()
{
    $args = array(
        'public' => true,
        'hierarchical' => true
    );
    register_taxonomy('Categories', array('members'), $args);
}

add_action('init', 'members_taxonomys');

And in single-members.php I made this code to call my categories:

<?php if(have_posts()):?>
<?php while(have_posts() ): ?>
    <?php 
        the_category(' ');
    ?>

And for some reason, it didn't work. Feel free to ask more questions or more details.

CodePudding user response：

1. Hi, first of all you need to change the name of your custom taxonomy and give it a label:

function members_taxonomys()
{
    $args = array(
        'label'                 => 'My categories', // Label
        'public' => true,
        //'show_admin_column'     => true,
        'hierarchical' => true
    );
    // Custom category 
    register_taxonomy('my_categories', array('members'), $args);
}

add_action('init', 'members_taxonomys');

2. When creating your own post type, you need remove rewrite rules:

function members_post_type()
{
    $args = array(
        'labels' => array(
            'name' => 'Members',
            'singular_name' => 'Member',
            'all_items' => 'All members'
        ),
        // 'hierarchical' => true,
        'public' => true,
        'query_var'           => true,
        'rewrite'             => true,
        'has_archive' => true,
        'supports' => array('title', 'editor' , 'thumbnail'),
        'menu_icon' => 'dashicons-groups'
    );
    register_post_type('members', $args);

    flush_rewrite_rules(false); // Remove rewrite rules 
}

3. Create a new members post and assign your custom taxonomy to it

4. Then you need to replace the the_category(); function because it works with the standard category taxonomy, you need to use get_the_terms function

<?php if(have_posts()):?>
<?php while(have_posts() ): the_post(); ?>
    <?php 
       $categories = get_the_terms($post, 'my_categories');
       if(!empty($categories)) {
           ?><ul><?php
                foreach($categories as $cat) {
                    print "<li>$cat->name</li>";
                }
           ?></ul><?php           
       }        
    ?>
<?php endwhile; ?>
<?php endif;?>