如果这是您自己的类，并且您可以修改它，那么您可以将该类的实例作为附加参数传递给过滤器回调：

class Foo {

   ...constructor, etc. 

   function to_filter() {
      $output = \'<div class="wrap">\';
      $output .= $this->another_function();
      $output .= more html

      return apply_filters( \'to_filter_name\', $output, $this );    
      } 
}

function filter_foo( $output, $foo ) {
    $output .= $foo->another_function();

    return $output;
}
add_filter( \'to_filter_name\', \'filter_foo\', 10, 2 );