Need tools for managing multiple workbooks

Are there any third party add-ons that would allow you to add workbooks where you would a worksheet? In other words, you click on a "sheet" for example called "another_workbook" and it opens a new workbook with its own specific sheets and/or embedded workbooks.

I'm trying to avoid the complex file management required by having dozens of linked workbooks each having dozens of linked sheets. I want just one file that has all this hierarchy in it.