CPT Rewrite

functions.php

/**
 * Register Community Custom Post Type
 */
function community_post_type() {

    $labels = array(
        'name'                  => 'Communities',
        'singular_name'         => 'Community',
        'menu_name'             => 'Communities',
        'name_admin_bar'        => 'Communities',
        'archives'              => 'Community Archives',
        'attributes'            => 'Community Attributes',
        'parent_item_colon'     => 'Parent Community:',
        'all_items'             => 'All Communities',
        'add_new_item'          => 'Add New Community',
        'add_new'               => 'Add New',
        'new_item'              => 'New Community',
        'edit_item'             => 'Edit Community',
        'update_item'           => 'Update Community',
        'view_item'             => 'View Community',
        'view_items'            => 'View Communities',
        'search_items'          => 'Search Communities',
        'not_found'             => 'Community Not found',
        'not_found_in_trash'    => 'Not found in Trash',
        'featured_image'        => 'Featured Image',
        'set_featured_image'    => 'Set featured image',
        'remove_featured_image' => 'Remove featured image',
        'use_featured_image'    => 'Use as featured image',
        'insert_into_item'      => 'Insert into item',
        'uploaded_to_this_item' => 'Uploaded to this Community',
        'items_list'            => 'Communities list',
        'items_list_navigation' => 'Communities list navigation',
        'filter_items_list'     => 'Filter Communities list',
    );
    $rewrite = array(
        'slug'                  => '/%category%/communities'
    );
    $args = array(
        'label'               => 'Community',
        'labels'              => $labels,
        'supports'            => array( 'title', 'editor', 'excerpt', 'thumbnail', 'custom-fields', ),
        'taxonomies'          => array( 'category' ),
        'public'              => true,
        'show_ui'             => true,
        'show_in_menu'        => true,
        'menu_position'       => 5,
        'menu_icon'           => 'dashicons-universal-access',
        'show_in_admin_bar'   => true,
        'show_in_nav_menus'   => true,
        'can_export'          => true,
        'has_archive'         => true,
        'exclude_from_search' => false,
        'query_var'           => true,
        'query_var'           => true,
        'rewrite'             => true,
        'hierarchical'        => true,
        'capability_type'     => 'page',
        'show_in_rest'        => true,
    );
    register_post_type( 'communities', $args );

}
add_action( 'init', 'community_post_type',99 );


/**
 * Add category slug to community post links
 * @param  $permalink
 * @param  $post
 * @return $permalink
 */

function commmunity_posts_link( $permalink, $post ) {
    if( $post->post_type == 'communities' ) {
        // $resource_terms = get_the_terms( $post, 'resource_type' );
        $resource_terms = get_terms( array(
            'taxonomy' => 'category',
            'hide_empty' => false
        ));
        $term_slug = '';
        if( ! empty( $resource_terms ) ) {
            foreach ( $resource_terms as $term ) {
                // you should prob do some conditional checking here
                // such as 'featured' or something, otherwise you have
                // too much duplicate content
                if( $term->parent != 0 ) {
                    continue;
                }
                $term_slug = $term->slug;
                break;
            }
        }
        $permalink = trailingslashit(get_home_url()) . $term_slug . "/communities/" . $post->post_name;
    }
    return $permalink;
}
add_filter('post_type_link',"commmunity_posts_link",10,2);

/**
 * Adds the rewrite rules
 * @param  $wp_rewrite
 */
function communities_cpt_rewrite_rule($wp_rewrite) {

    $post_type = 'communities';
    $terms = get_terms( array(
        'taxonomy' => 'category',
        'hide_empty' => false
    ));

    $rules = array();
    foreach ($terms as $term) {
        $rules[ $term->slug .'/communities'. '/([^/]*)$'] = 'index.php?post_type=' . $post_type. '&category=$matches[1]&name=$matches[1]';
    }
    // merge with global rules
    $wp_rewrite->rules = $rules + $wp_rewrite->rules;

}
add_filter('generate_rewrite_rules', 'communities_cpt_rewrite_rule');