“一個上の”…・・・?

class Hoge
{
 public Hoge hogeParent;
 public Hoge hoge_1;

 public Hoge(int num, Hoge parent)
 {
  hogeParent = parent;
  if (num > 1)
  {
   hoge_1 = new Hoge(num / 2, this);
  }
 }
}

Hoge hoge_top = new Hoge(64, null);