How do I search sub-folders and sub-sub-folders in Google Drive?

Question

This is a commonly asked question.

The scenario is:-

folderA____ folderA1____folderA1a
       \____folderA2____folderA2a
                    \___folderA2b

... and the question is how do I list all the files in all of the folders under the root folderA.

Answer 1

EDIT: April 2020 Google have announced that multi-parent files is being disabled from September 2020. This alters the narrative below and means option 2 is no longer an option. It might be possible to implement Option 2 using shortcuts. I will update this answer further as I test the new restrictions/features We are all used to the idea of folders (aka directories) in Windows/nix etc. In the real world, a folder is a container, into which documents are placed. It is also possible to place smaller folders inside bigger folders. Thus the big folder can be thought of as containing all of the documents inside its smaller children folders.

However, in Google Drive, a Folder is NOT a container, so much so that in the first release of Google Drive, they weren't even called Folders, they were called Collections. A Folder is simply a File with (a) no contents, and (b) a special mime-type (application/vnd.google-apps.folder). The way Folders are used is exactly the same way that tags (aka labels) are used. The best way to understand this is to consider GMail. If you look at the top of an open mail item, you see two icons. A folder with the tooltip "Move to" and a label with the tooltip "Labels". Click on either of these and the same dialogue box appears and is all about labels. Your labels are listed down the left hand side, in a tree display that looks a lot like folders. Importantly, a mail item can have multiple labels, or you could say, a mail item can be in multiple folders. Google Drive's Folders work in exactly the same way that GMail labels work.

Having established that a Folder is simply a label, there is nothing stopping you from organising your labels in a hierarchy that resembles a folder tree, in fact this is the most common way of doing so.

It should now be clear that a file (let's call it MyFile) in folderA2b is NOT a child or grandchild of folderA. It is simply a file with a label (confusingly called a Parent) of "folderA2b".