Google-drive – How to a guest viewer search the Google drive contents

In addition to Chris' method, if all you require is access to a single Google doc, consider creating a new Document which is set to allow anyone with the link to edit (no-sign in required).

Then you just need to give the link to whoever you want to be using the document. It would be impossible to access the page without the link and you dont need them to login to edit the document.

This would also be beneficial because using this method the document remains owned by an employee rather than the guest account.

The easiest way would be to make a top level folder called "Business" in your business account, and a "Personal" folder at the top level in your personal account

Then place ALL your business folders below "Business" in your business account and similar in your personal account.

Google Drive doesn't really see each folder as separate in that way. Even if a friend of yours shares an "Account" folder with you, and you already have 2 "Account" folders, it won't nest that any differently.

I personally have "email@address.com" as my top level in my different Google Apps accounts, and I bookmark that page (where I have browsed into that folder) in my toolbar. This seems to be the best solution for me, and at a glance it is very obvious which folder I want.