Do some searching by keyword, then focus on a few titles that look promising, and see what subject headings describe the works.
Some subject headings to play around with:
Moonlight: screening black queer youth by 
Screening Queer Memory: LGBTQ pasts in contemporary film and television by 
Queering the Migrant in Contemporary European Cinema by 
Queer Representations in Chinese-Language Film and the Cultural Landscape by 
Desire after Dark: contemporary queer cultures and occultly marvelous media by 
Queer Timing: the emergence of lesbian sexuality in early cinema by 
Sisters in the Life: a history of out African American lesbian media-making by 
Girls Will Be Boys by 
Chinese Lesbian Cinema by 
Homecoming Queers by 
Lesbian Potentiality and Feminist Media in The 1970s by 
Cold War Femme: lesbianism, national identity, and Hollywood cinema by 
Search in Books & Media to find print and online books, films, music--everything EXCEPT articles (which can be found in databases and online journals).
If you're specifically looking for movies, you can Search and Find - Film & Video. And to find materials by specific film directors, screenwriters, cinematographers and actors, search by "author" in the dropdown menu.
Duke Libraries also has a wealth of streaming films available to watch on several different platforms. Check them out!
Film Analysis: a Casebook by 
Encyclopedia of Women and Gender, Two-Volume Set by 
Encyclopedia of Sex and Gender by 
The Oxford Handbook of Queer Cinema by 
Film Analysis: an Introduction by 
Feminist Film Theory by 
Queer Cinema in America by 
Queer African Cinemas by 
Contemporary Black American Cinema by 
Daughters of Desire by 
Out in the Periphery: Latin America's gay rights revolution by 
