When I share a folder, will all sub-folders be shared (accessible) as well?

Yes.

If you have a folder named folderX and inside this folder you have folder1, folder2 and folder3, all users with access to folderX will have access to Folder1,2 and 3 and the contents of all this folders.

Subfolders inherit permissions from the top folder.

Awesome. Thanks Alexis!

Alexis,

I am pretty new to Dropbox for Business so please overlook my newbie question.  Even though subfolders inherit permissions from the upper level folder, are you referring to Viewer, Editor, and Owner or Read vs Read/Write or something else.

The way I want to structure the company's documents would be easiest in a tree structure but some folders need to be private to a segment of the users, and some accessible by all.

The way the documents are structured now is a flat hierarchy with access to each document thru links.  This is very cumbersome and requires too much maintenance of the links as things change.

Any suggestions?

Thanks

Mel

are you referring to Viewer, Editor, and Owner or Read vs Read/Write or something else. 

All. 

It is not possible to alter child folders (in Alexis's example that would be folder1, folder2 etc) properties independently of parent. 

Ok.  That's too bad but I'll figure out how to live with it.  Thank you for the reply.

@Mel:

Why you don't create different shares.

For example: a share for accounting department, a share for legal department, a share por HR, a share for IT, a share for sales, etc.

@Mel K:

I share your disappointment. I wish you could share with additional users in the subfolders that are not present in the main folder. The ability to do this would help with simplifying folder organization.

We have different top level folders (I think you mean shares) for the administrative functions, but we have about 120 groups and committees that should have restricted access to their members.  Having one share for those groups and committees simplifies the dropbox but is difficult otherwise. Also, then, each group can access the files of the other groups which we don't want.  I guess the root of the problem is that there are just too many top level folders.  Or, am I missing something?