What are you doing with the section planes in your model. Section planes don't actually cut through the model. It's more like an X-ray imaging of a body.
What do you mean by "I don't seem to be able to export a section view of my model that has multiple groups with any accuracy"?
It would help if you'd upload an example SketchUp model file so we can see what you are working with.
What version of SketchUp are you using? Your profile says 2018 Free/Make which is impossible as there never has been a version like that.