Navigation:  Calculation Modules > Analysis > ENERCALC 3D > Ribbons > Create > Levels

Create > Levels prompts you with the following dialog.  

 

 

 

It allows you to define physical levels in the model.  Once levels are defined, you are able to view a level plan by using the command View > Hide All Except Level.  To reveal the hidden parts of the model, click View > Show All.