The author does not know what "parent folder" means. He thinks it is something online. Wrong. A parent folder is in the hierarchy of bookmarks, for instance,
Phones/Samsung/Galaxy S10
Phones/Sony/Sony Xperia
The parent folder of Galaxy S10 is Samsung and it's parent folder is Phones.
There are no parent folders online. The example shows URLs. Who wants to do that when simply cutting off the last "/" in the address bar does the same thing.