STEP 3- Sweep

To create the inner door frame, I go to Create> Sweep> Pick A Path > Pick 3D path and change the view to 3D View to ensure I am clicking the frame.

Once I am done, I click finish and head back to the reference level page to edit the profile by going Project Browser> Ref Level > Modify Tab> Edit Profile > Pick Lines . Ensure to lock each lines that had been created. After that, click trim and trim out the extra lines.

Move to 3D View and the inner door frame had been created.