And what's more, the Hollywood star's youngest daughters Sunday and Faith, also make appearances in the much-anticipated show.
Talking to News.com.au, Nicole revealed: "They're used to being extras, but they did fives days in the freezing New York cold, never complained, and didn't get any special treatment.
"And then one day they came home and said, 'We got a line!'"
VIDEO: Nicole Kidman and her daughters surprise Keith Urban
The mother-of-four added that Sunday in particular is passionate about filmmaking and creates mini movies every weekend.
"My oldest wants to be a filmmaker, and she makes films every weekend," she explained.
Nicole Kidman's daughters Sunday and Faith both have roles as extras in The Undoing
"The little one is battling to get in them, but she's had a tantrum and wouldn't say the lines."
And even though Sunday's mum is a famous movie star, she hasn't been getting special treatment either.
The actress revealed: "And I actually got fired last weekend."
In The Undoing, Nicole plays Grace Fraser, whose life unravels after her husband Jonothan (played by Hugh) disappears following a violent death in the city, which leads to a chain of revelations.
Nicole and co-star Hugh Grant in The Undoing
Nicole has been keeping busy during the pandemic, and is currently staying in Australia with Keith Urban and her daughters while she films the upcoming Hulu series, Nine Perfect Strangers.
Nicole and her family are used to travelling around the world together, and have homes in Nashville, London, LA and New York.
In an interview published in HELLO! in August, she reflected on how the pandemic has transformed their lives.
Nicole's daughter Sunday is passionate about filmmaking
"We travel together, so we are always together, but never where you are in a house and you can't go to the store, to a restaurant of the movies," she said.
"Staying home, doing school from home and all of those things that everyone has been doing is a completely different life for us."
The Undoing will be available on Sky Atlantic & NOW TV from 26 October
Read more HELLO! US stories here
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