可以支持三级菜单吗？

我有个问题就是是否可以支持三级路由这样子的显示呢？不知道是否是操作的问题，我实现不了诶

The issue asks whether the admin system can display a third-level route or menu. Start by examining the repository's routing and menu implementation, then determine the intended nesting behavior and how existing menu examples are structured. Done means a documented or tested third-level display behavior, but the issue does not name files or define the expected result.

Written by the indexing model from the issue text.