It seems to be all of the ones I've tried so far.  All of them strip the folder structure when imported to Databricks.

These have the incorrect "DE Access Course Material" video instructions:

https://customer-academy.databricks.com/learn/course/1174/introduction-to-unity-catalog

https://customer-academy.databricks.com/learn/course/1177/unity-catalog-patterns-and-best-practices

This one has no download/import instructions, but the course content assumes you are following along in a notebook, and it does have a "Course DBC" download at the bottom of the TOC:

https://customer-academy.databricks.com/learn/course/2469/get-started-with-databricks-for-data-engin...