当在另一个下拉列表中进行选择时，如何在Django的管理员中过滤下拉列表

I have two dropdownlists in a Django admin site. For example, I have SelectCountry and SelectRegion. Region has a foreignkey relationship to Country. How do I ensure that when a Country is selected, the Regions are filtered based on that Country?I have two dropdownlists in a Django admin site