The information in this article applies to:
I would like to create a split level entry to a house. How can I do that?
A split level entry consists of a landing with a floor height between the first floor and the basement. This kind of entry can be created by contolling the floor and ceiling heights in your plan.
From floor 0 you can now turn on Reference Floor Display by clicking Tools> Reference Floors> Reference Floor Display and continue with drawing the stairs.
And that is all there is to it. You can place a door and adjust it's height and finish the rest of the plan.