Object flipping

Simply taking an existing item and being able to turn on mirroring. Examle, I want to have two staircases flanking a doorway, with the base of the stairs meeting with their bottom stair at the base of the door. We have one L shaped staircase that will work, but there is no staircase to put on the other side of the doorway.
Visual - The dual staircase at the bottom of this page
https://www.tollbrothers.com/blog/7-popular-types-of-staircases-in-home-design/