除了我之前的答案之外，添加以下代码。应该很好用

add_filter( \'views_edit-books\', \'add_filter_link\' );
function add_filter_link( array $views ) {
    $url = add_query_arg( array(\'bfilter\'=>\'parents\',\'post_parent\'=>0,\'post_type\'=>\'books\'), \'edit.php\' );
    $views[ \'post_parent\' ] = sprintf(
        \'<a href="%1$s"%2$s>%3$s</a>\',
        esc_url( $url ),
        ( is_filter_active() ) ? \' class="current" aria-current="page"\' : \'\',
        \'Post Parents\'
    );
    return $views;
}

function is_filter_active() {
    return (filter_input( INPUT_GET, \'bfilter\' ) ===\'parents\');
}

function make_post_parent_public_qv() {
    global $pagenow;
    if ( is_admin() && $pagenow == \'edit.php\' )
        $GLOBALS[\'wp\']->add_query_var( \'post_parent\' );
}
add_action( \'init\', \'make_post_parent_public_qv\' );