The Razor's Edge (1946)

Well-to-do Chicagoan, Larry Darrell, breaks off his engagement to Isabel and travels the world seeking enlightenment, eventually finding his guru India. Isabel marries Gray, and following the crash of 1929, is invited to live in Paris with her rich, social climbing, Uncle Elliot. During a sojurn there, Larry, having attained his goal, is reunited with Isabel. While slumming one night Larry, Isabel and company are shocked to discover Sophie, a friend from Chicago. Having lost her husband and child in a tragic accident, Sophie is living the low-life with the help of alcohol and an abusive brute. Larry tries to rehabilitate her, but his efforts are sabotaged by Isabel who tries in vain to reignite Larry's interest in herself.

IMDb: https://www.imdb.com/title/tt0038873