Question: William Friedkin and John Quigley both shared what occupation?

Context paragraphs:
John Quigley (Pennsylvania): John Quigley is a former Secretary of the Pennsylvania Department of Environmental Protection, having been nominated by Pennsylvania Governor Tom Wolf and confirmed in June 2015 and serving until his resignation in May 2016.  From 2009 to 2011, Quigley served as secretary of the Pennsylvania Department of Conservation and Natural Resources.  Prior to his appointment as secretary, Quigley worked for DCNR in several capacities, including overseeing strategic initiatives and operations, and as chief of staff.  He is the first and only person in the history of Pennsylvania to hold the positions of both DCNR and DEP Secretary.

John Quigley (hurler): John Quigley (born 1949) is a former Irish sportsperson.  He played hurling with his local club Rathnure and with the Wexford senior inter-county team in the 1960s and 1970s.

Exorcist II: The Heretic: Exorcist II: The Heretic is a 1977 American supernatural horror film directed by John Boorman and written by William Goodhart.  It stars Linda Blair, Richard Burton, Louise Fletcher, Max von Sydow, Kitty Winn, Paul Henreid and James Earl Jones.  It is a sequel to William Friedkin's 1973 film "The Exorcist" based on the 1971 novel by William Peter Blatty and the second installment of "The Exorcist" franchise.  The film is set four years after the original film and centers on the now 16-year-old Regan MacNeil, who is still recovering from her previous demonic possession.

William Friedkin: William Friedkin (born August 29, 1935) is an American film director, producer and screenwriter best known for directing "The French Connection" in 1971 and "The Exorcist" in 1973; for the former, he won the Academy Award for Best Director.  Some of his other films include "Sorcerer", "Cruising", "To Live and Die in L.A.", "Jade", "Rules of Engagement", "The Hunted", "Bug", and "Killer Joe".

John Quigley (author): John Quigley (born 1925) is a Scottish author known for his historical novel "King's Royal" (1975) about the invention of blended whisky in mid-nineteenth century Glasgow.  A 1983 BBC television series was based on the novel.

John Quigley (producer): John "Quig" Quigley is an American film director, producer, editor, and writer.  His professional career began in music video production and directing in Detroit, Michigan, in the early 1990s.  Since then, Quigley has produced and directed music videos and audio-visual projects for artists including – Eminem, 50 Cent, Kid Rock, Christina Aguilera and Tori Amos.  As founder and owner of the production company, Chrome Bumper Films, Quigley has also created and directed award-winning documentaries and commercials.

Killer Joe (film): Killer Joe is a 2011 American Southern Gothic black comedy crime film directed by William Friedkin.  The screenplay by Tracy Letts is based on his 1993 play of the same name.  The film stars Matthew McConaughey in the title role, Emile Hirsch, Juno Temple, Gina Gershon, and Thomas Haden Church.  Friedkin and Letts had similarly collaborated on the 2006 film "Bug".

To Live and Die in L.A. (film): To Live and Die in L.A. is a 1985 American action thriller film directed by William Friedkin and based on the novel by former U.S. Secret Service agent Gerald Petievich, who co-wrote the screenplay with Friedkin.  The film features William Petersen, Willem Dafoe and John Pankow among others.  Wang Chung composed and performed the original music soundtrack.  The film tells the story of the lengths to which two Secret Service agents go to arrest a counterfeiter.

Sorcerer (film): Sorcerer is a 1977 American existential thriller film directed and produced by William Friedkin and starring Roy Scheider, Bruno Cremer, Francisco Rabal, and Amidou.  The second adaptation of Georges Arnaud's 1950 French novel "Le Salaire de la peur", it has been widely considered a remake of the first adaptation, the 1953 film "The Wages of Fear".  Friedkin, however, has disagreed with this assessment.  The plot depicts four outcasts from varied backgrounds meeting in a South American village, where they are assigned to transport cargoes of nitroglycerin.

The Thin Blue Line (1965 film): The Thin Blue Line was the second of three documentaries William Friedkin made for producer David Wolper.  It focused on the police force, and the experience making it influenced Friedkin on "The French Connection".

Supporting paragraphs: William Friedkin John Quigley (producer)
Answer: film director