Sports Night, an early Aaron Sorkin show, was about the behind-the-scenes workings of a cable sports show: episodes often started with a segment of the show-within-a-show, and their first commercial break was also the viewer’s first commercial break.
I can’t remember if the same conceit was ever used on Studio 60 On The Sunset Strip or The Newsroom, but they used a similar one on the former for the opening title/credits: sometimes episodes would start with the cold open of the show-within-a-show, and when the director would yell “roll VTR!” (i.e., start the video tape recording of the title/credits) the actual show’s opening VTR would run.