What film was Nicole Kidman in based on a 1960s sitcom?

The film you're thinking of is "Being the Ricardos" (2021). It's a biographical drama film about the tumultuous week in the lives of Lucille Ball and Desi Arnaz, the stars of the iconic 1950s sitcom "I Love Lucy."

While the film doesn't directly adapt any specific episodes of "I Love Lucy," it draws heavily on the real-life experiences and behind-the-scenes dynamics of the show's production.