// Add the custom columns to the book post type: add_filter( 'manage_book_posts_columns', 'set_custom_edit_book_columns' ); function set_custom_edit_book_columns($columns) { $columns['book_author'] = __( 'Sub-Author', 'your_text_domain' ); $columns['publisher'] = __( 'Publisher', 'your_text_domain' ); return $columns; // To add after one column // $n_columns = array(); // foreach($columns as $key => $value) { // if ($key=='title'){ // $n_columns[$key] = $value; // $n_columns['book_author'] = __( 'Author', 'your_text_domain' ); // $n_columns['publisher'] = __( 'Publisher', 'your_text_domain' ); // } // $n_columns[$key] = $value; // } // return $n_columns; } // Add the data to the custom columns for the book post type: add_action( 'manage_book_posts_custom_column' , 'custom_book_column', 10, 2 ); function custom_book_column( $column, $post_id ) { switch ( $column ) { case 'book_author' : $terms = get_the_term_list( $post_id , 'book_author' , '' , ',' , '' ); if ( is_string( $terms ) ) echo $terms; else _e( 'Unable to get author(s)', 'your_text_domain' ); break; case 'publisher' : echo get_post_meta( $post_id , 'publisher' , true ); break; } }