I have a misunderstanding regarding the channels that are available to be attached to a project.
First, I select a base channel for the project, then, on the child drop-down menu, you are allowed to select also other base channels (but referenced as children?).
I am not sure why is it possible as I thought a project should refer only to one base channel and its possible children channels.
Does it make sense to have a project with multiple base channel and so potentially different OS versions?
My possible answer is that you may want to add some custom channels with customs packages for the organization?