Project within a Project - nesting

Project within a Project - nesting

We have large implementations and have many projects that fall within projects.  It would be great if we could figure out a file folder structure...For example: 

- Customer Implementations (Heading)
     -  Customer A (Project)
          -  Training (Project within a project)
          -  Hardware (Project within a project)
     -  Customer B (Project)
          -  Integrations (project within a project)
          -  Training (project within a project) 

Each project may have a different Team assigned.  

In a large organization with many projects, some sort of organization will be required.