Australian star Nicole Kidman says her experience as the mother of adopted children meant she closely related to her character in the movie "Lion", tipped as an Oscar favourite.

Garth Davis's film about a young man from India adopted by an Australian family who searches for his long-lost blood relatives using Google Earth, has already received a Golden Globe nod for best drama motion picture.

It also won nominations in the supporting actor categories for Kidman and Dev Patel, with the pair repeating the feat for the 23rd Screen Actors Guild awards.

Kidman adopted two children with ex-husband Tom Cruise -- Isabella and Connor -- and said she immediately felt a connection with the woman she portrayed, Sue Brierley who adopted Saroo, played by Patel.

"She came up to Sydney and we just sat in my apartment ... and just started talking," Kidman told the Australian Broadcasting Corporation ahead of the film's Australian premiere on Monday evening.

"I told her a lot about myself, and it was almost like she already knew a lot, and not stuff I had talked about publicly, but just sensations and feelings."

Brierley told the broadcaster the two women immediately bonded.

"With your children being adopted, it was important to me that someone be on my page," she said in explaining why she wanted Kidman in the role after discovering her story was going to be made into a film.

"We'd both had a tough patch. Because I lost my mother, and your (Kidman's) father passed away, really within one month, so we were rather raw emotionally at that time."

Kidman said that being an adoptive parent helped her understand Brierley's experiences.

"We have similar ways in which we wanted to adopt," Kidman said.

"I just felt ever since I was young that I was going to adopt a child. Mine wasn't the vision Sue had exactly, but pretty similar, and we both made it happen and that is weird to have the same thing."

Kidman, who also has two daughters with country music star husband Keith Urban, added that getting the role "was just meant to be, it was mapped out in the stars, so to speak".

The 89th Academy Awards are in Los Angeles on February 26.