Use Analytical Automation tools to generate an structural analytical model from physical elements, or generate physical model elements from analytical model elements .
Starting in Revit 2023, the structural analytical model is separate from the physical model. Prior to this, the analytical model and the physical model were connected. The elements used to create model contained both representations, physical and analytical. Separating the models gives more flexibility to modeling workflows. You are free to model the physical model and the analytical model to each of their unique needs. Analytical Automation makes the process of developing one model from the other almost automatic.
Structural Analytical Model panel
(Analytical Automation). In the dialog, select from the options based on the type of model you are starting with. 
  Select the inputs for the graph, and run the tool. For additional information on the values used for the inputs see Analytical to Physical Automation and Physical to Analytical Automation.
For a brief overview of the workflow, review the video.