Hi,
What I would do is add a node to the data source and call it "StepNo". This node would not show in the canvas, but instead I would use it only to control what is shown to the user.
I would have a section for Location and a section for Project.
When the form opens I would have a rule that sets StepNo to 1. Then I would have a rule that would hide the Project Section when StepNo is equal to 1.
When the user clicks the button to go to the next step, I would have a rule that sets StepNo to 2. Then I
would have a rule that would hide the Location Section when StepNo is
equal to 2.
Does that make sense?