I did a cursory search to see if this has been done before and didn’t find anything, so here goes.
I caught a bit of “Wall Street” yesterday, wherein Martin Sheen plays Charlie Sheen’s father. What other movies/TV shows/whatever feature real life parents playing their real life children’s parents?
It Runs In The Family had Kirk Douglas playing Michael Dougas’s father and Diana Douglas playing his mother, as well as having Cameron Douglas playing Michael Douglas’s son and Kirk and Diana Douglas’s grandson. Which is some kind of Hollywood Nepotism Nirvana or something…
In the BBC series Jam & Jerusalem (released in the US as Clatterford) has Jennifer Saunders real daughters playing her own daughters. Her character talks about a made-up son and a made-up husband (she’s married to Ade Edmondson) but she’s always bickering with her real life teenage girls.
In a little bit different take on the OP in The Ten Commandments Charlton Heston played Moses of course, but the part of the baby Moses was played by Frasier Heston. Later on, in the mini-series Moses the Lawgiver Burt Lancaster played the older Moses, and his son played Moses as a young man.