This uses flooring under the path, you can see the bare flooring in the middle section where the path doesnt reach, but there is a mix of wooden pathing and bare floor on the lower section and concrete mix on at the bottom, I prefer having the path visible but flush with the flooring just to make it easier to manage!
So for some of those corner pieces in grid layout you have to decided if you want the barrier to show or not as you cant tell it to only have a barrier on one side:
Pathing on the concrete floor, with the generator there I had to give up on doing the full grid layout
So yeah I already put in a request to have the floor building tiles treated as path objects, at least even if only for staff, would make things much easier especially as Blueprints do not save paths, so each time I use this blueprint I have to redo the pathing. I also put in a feature request to have elevators and ladders, again even if just for staff would be useful as the stairs and ramp paths take up a lot of real estate!