Unfortunately, there is no way that I'm aware of to accomplish this using pipe networks. As you can see, structures are not one of the things you can project onto a section view.
You could create blocks on your structures that you then project but they won't change as your structures change.
Sorry I don't have a better solution for you.
Perhaps this is a useful feature that Autodesk could include in version 2024, after they've implemented the holographic-cloud-based-silt-monitoring toolset that we are all clamouring for.
I am trying to do just what you describe above (in Civil 3D 2011). I have an existing sample line group and I want to add a new pipe network to the sources but it is not listed under the availible sources. Did the pipe network have to be in existence when I created the sample lines? Unfortunately I am working somewhat backwards to recreate some things in some drawings for a project I just took over at a new company, so I am not taking the most straight forward approach to some things.
I went and created another sample line group to just see if it would be there. Once I did that the pipe network showed up as a source in the new one, but also in the old sample line group. I am not sure if now if I just missed it before, or if there was some type of reference when I went thought the creation process again. regardless IT is possible to add newly created pipe networks as a source to old sections.
Thanks for your input!