About grouping projects
For example, a good use for a grouping project is to contain the different platforms for a software application. If all of your projects are structured into one large hierarchy, check out new project versions by using the Copy Project dialog box Subprojects list.
As an example, assume that you want to group different platforms of a project called toolkit_top-3.0. It groups toolkit-win and toolkit-unix together.
To set up the toolkit_top-3.0 grouping project, set up uniquely named projects.
Two projects with the same name cannot be subprojects within the same parent project. For example, toolkit-win and toolkit-unix cannot be grouped together in the same project.
To group projects with the same name, create an extra level of projects with unique names. A single project with a work area cannot contain subprojects whose work areas are not visible to the parent project. Therefore, turn off work areas, which is described in Creating a grouping project.