Question: Val Guest and Robert Butler, have which mutual occupation?

Context paragraphs:
Bees in Paradise: Bees in Paradise is a 1944 British musical comedy film directed by Val Guest and starring Arthur Askey, Anne Shelton and Peter Graves.  It was produced by Edward Black at Gainsborough Pictures.  Co-written by director Val Guest and comic Marriott Edgar, who wrote for Will Hay and the Crazy Gang and composed some of Stanley Holloway's famous monologues; this is a lesser known Askey vehicle.

It's a Wonderful World (1956 film): It's a Wonderful World is a 1956 British musical film directed by Val Guest and starring Terence Morgan, George Cole, Mylène Demongeot (listed in the credits as Mylène Nicole) and Kathleen Harrison.  It also features Dennis Lotis, a popular singer at the time.  It was made at Shepperton Studios.  Songs include: "Rosanne", "When You Came Along", "Girls!  Girls!  Girls!"  (Ted Heath, Moira Heath), "A Few Kisses Ago" (Robert Farnon, Val Guest), and "The Hawaiian War Chant" (Ted Heath).

Robert Butler (director): Robert Butler (born November 16, 1927) is an American film director and Emmy Award-winning television director.  He is best known for his work in television, where he directed the pilots for a number of influential series including "Star Trek" and "Hill Street Blues".

Penny Princess: Penny Princess is a 1952 British Technicolor comedy written and directed by Val Guest for his own production company, Conquest Productions.  The film stars his future wife Yolande Donlan, who was Guest's production company partner, and features Reginald Beckwith, the other partner in Conquest Productions.  Dirk Bogarde plays the leading man.

When Dinosaurs Ruled the Earth: When Dinosaurs Ruled the Earth is a 1970 British prehistoric monster horror film from Hammer Film Productions, produced by Aida Young, written and directed by Val Guest, that stars Victoria Vetri.  Guest's screenplay was based on a treatment by J. G. Ballard (author of "Empire of the Sun"), and nominated for an Oscar for its visual effects.  This was the third in Hammer's "Cave Girl" series, preceded by "One Million Years B.C." (1966) and "Slave Girls" (1967).  It was followed by "Creatures the World Forgot" (1971).

The Boys in Blue: The Boys in Blue is a 1982 British comedy film directed by Val Guest and starring Tommy Cannon, Bobby Ball, Suzanne Danielle and Roy Kinnear.  It is loosely based on the 1938 Will Hay film "Ask a Policeman", which Guest co-wrote.  Some policemen who have failed to make any arrests are threatened with dismissal, and begin to invent crime to justify their existence.  It was the final feature film that Guest directed.

Val Guest: Valmond Maurice "Val" Guest (11 December 1911 – 10 May 2006) was an English film director and screenwriter.  Beginning as a writer (and later director) of comedy films, he is best known for his work for Hammer, for whom he directed 14 films, and science fiction films.  He enjoyed a long career in the film industry from the early 1930s until the early 1980s.

Carl Butler: Carl Robert Butler, known professionally as Carl Butler, (June 2, 1927 – September 4, 1992) was an American country music singer-songwriter and one half of the husband-and-wife duo Carl and Pearl Butler.  Carl and Pearl Butler had one of the biggest-selling singles of 1962, "Don't Let Me Cross Over".  A later single, "Too Late to Try Again", hit #9 on the country charts in 1964 for them, while the B side, "My Tears Don't Show", crept up to #36.  Butler wrote those 2 songs and also "If Tear Drops Were Pennies" (twice a top ten country hit - Carl Smith in 1951 and Dolly Parton and Porter Wagoner in 1973 - and also a minor hit (#21) on the pop charts for Rosemary Clooney in 1951) and "Crying My Heart Out Over You" (written with Lester Flatt, Earl Scruggs, and Earl Sherry, the song charted for Flatt and Scruggs in 1960, but is best known from the 1982 Ricky Scaggs version, which hit #1).

Allan Butler: Allan Robert Butler, OAM (born 1976) from Tumut, New South Wales is an Australian Paralympic athlete.  In 1993, Butler moved to Canberra to take up a residential scholarship at the Australian Institute of Sport.

Yesterday's Enemy: Yesterday's Enemy is a 1959 Hammer Films British war film in MegaScope directed by Val Guest and starring Stanley Baker, Guy Rolfe, Leo McKern and Gordon Jackson set in the Burma Campaign during World War II.  It is based on a 1958 BBC teleplay by Peter R. Newman, who turned it into a three-act play in 1960.  Gordon Jackson repeated his role from the BBC teleplay as Sgt. Ian Mackenzie.  Columbia Pictures co-produced the film with Hammer Films in an agreement for five co-productions a year with Columbia providing half the finance.  The film was shot on indoor sets in black and white and Megascope.  The film has no musical score.  Director Val Guest later said that "Yesterday's Enemy" was one of his films of which he was the most proud.  In 2013, film magazine "Total Film" included "Yesterday's Enemy" in their list of "50 Amazing Films You've Probably Never Seen".

Supporting paragraphs: Val Guest Robert Butler (director)
Answer: film director