You can use the container project's properties to:
add new configurations
add projects to existing configurations
specify which variant of a subproject to build
To edit a configuration:
Right-click the container project and select Properties.
In the left pane, select Container Build Configurations.
Expand the project in the tree view on the right.
Select the configuration you want to edit. Configurations are listed as children of the container.
Click the Edit button at the right of the dialog. This opens the Container Build Configuration dialog (from the New Container wizard), which
you used when you created the container.
Make any necessary changes — add, delete, reorder projects, or change which make target or variant you want built for any given project.
Note: While editing a configuration, you can include or exclude a project from the build just by selecting or deselecting the project.
If you exclude a project from being built, it isn't removed from your container.
Click OK, then click OK again (to close the Properties dialog).