I don't know if this would help but the only movie I can think of is the Parent Trap with Lindsay Lohan
Real life or fictional ? For real life , a documentary named Twinsters. For fiction , Parent Trap (original with Hayley Mills)
There is that ninteen eighties comedy called twins about two twins seperated a birth. I do use comedy lightly though
Twins. Arnold Schwarzenegger and Danny Devito. Double Impact by Van Damme. Three Identical Strangers. It is a documentary so I don't know if it qualifies. The Parent Trap. A classic Disney movie from the 60s with a modern remake of the same name and some sequels. Big Business. Two set of twins mismatched at birth. The Man in the Iron Mask