Custom search file tree

I installed the free version of Avast for Mac to evaluate it. I do not see how to scan folders and all sub-folders and content. Also known as a “file tree”.

When I do a custom scan, it appears to only scan the folder and its direct contents but it is not “recursive” and does not scan sub-folders.

How do I scan subfolders?

https://forum.avast.com/index.php?board=5.0