Example: Add 'Favorited Count' column to products list

snippet.php

// Array of post types to include the column
function x_favorite_post_types() {
    return [
		'product' /* product post type */
	];
}


// Add custom column
add_filter('manage_posts_columns', 'x_add_favorited_users_column');
function x_add_favorited_users_column($columns) {

    $screen = get_current_screen();

    if (!$screen || !in_array($screen->post_type, x_favorite_post_types(), true)) {
        return $columns;
    }

    $columns['favorited_users'] = 'Favorited Count';
    return $columns;
}


// Output column value
add_action('manage_posts_custom_column', 'x_show_favorited_users_column_content', 10, 2);
function x_show_favorited_users_column_content($column, $post_id) {

    if ($column !== 'favorited_users') {
        return;
    }

    echo (int) bricksextras_post_favorite_count($post_id);
}