如何在 django admin 中按字段（多级关系）过滤？

How to filter by field of field (multi level relationship) in django admin?

模型设计如下：

class School(models.Model):
    name = models.CharField(max_length=50)

class Grade(models.Model):
    name = models.CharField(max_length=10)
    school = models.ForeignKey(School)

class Student(models.Model):
    name = models.CharField(max_length=100)
    grade = models.ForeignKey(Grade)

由于 Student 对象与 School 对象没有直接关系，我如何过滤 django-admin 以仅显示来自所选 school 的学生？

school_name = "your school name"
Students_in_school = Student.objects.filter(grade__school__name = school_name)