When you tried to underlay a floor only doors and windows were visible.
Revit site plan showing floor plan.
You will need to define the plan region using sketch tool.
If the view range intersects the geometry of a level in your main view that level cannot be used as an underlay in the main view.
About the view range the view range is a set of horizontal planes that control the visibility and display of objects in a plan view.
Please like this video.
In the project browser rename the newly created floor plan view to site.
In this video i show you everything you need to.
In the new plan dialog clear do not duplicate existing views.
Click view tab create panel plan views drop down floor plan.
In the new plan dialog clear do not duplicate existing views.
A floor or slab will be visible in a plan view if it is partially above the view depth or if it is within 4 feet approximately 1 21 meters of the bottom clip.
You can find this tool in view tab create panel plan views drop down plan region.
In the main floor level the bottom of the primary range is set to main floor with an offset of 1.
Draw the sketch as necessary then click finish.
Get this revit file here.
This issue occurs because there is an incorrect view range in the main view.
Open the site view.
Under floor plan views select the level on which to base the site view.
About plan regions to define multiple cut planes within a plan view use plan regions.
Create a site view as follows.