Question: Reginald Denham and Justin David Swibel, have which mutual occupations?

Context paragraphs:
The Jewel (1933 film): The Jewel is a 1933 British crime film directed by Reginald Denham and starring Hugh Williams, Frances Drake and Jack Hawkins.  The film is based on an Edgar Wallace novel "The Strange Countess".

The Village Squire: The Village Squire is a 1935 British comedy film directed by Reginald Denham and starring David Horne, Leslie Perrins, Moira Lynd and Vivien Leigh.  It was based on a play by Arthur Jarvis Black.  A village's amateur production of "MacBeth" is aided by the arrival of a Hollywood star.  This provokes the fierce resistance of the village squire who hates films.

Ladies in Retirement: Ladies in Retirement is an American 1941 film noir directed by Charles Vidor, and starring Ida Lupino and Louis Hayward.  It is based on a 1940 Broadway play of the same title by Reginald Denham and Edward Percy which starred Flora Robson in the lead role.

Borrow a Million: Borrow a Million is a 1934 British comedy film directed by Reginald Denham and starring Reginald Gardiner, Vera Bogetti and Wally Patch.  It was made at Wembley Studios as a quota quickie by the British subsidiary of the Fox Film Company.

Calling the Tune: Calling the Tune was a 1936 British musical drama film directed by Reginald Denham and Thorold Dickinson and starring  Adele Dixon, Sally Gray and Sam Livesey.  It was based on a play written by the Irish MP and novelist, Justin Huntly McCarthy first published in 1913.  It was made at Ealing Studios The film's sets were designed by the art director R. Holmes Paul.

Lieutenant Daring R.N.: Lieutenant Daring R.N. is a 1935 British adventure film directed by Reginald Denham and starring Hugh Williams, Geraldine Fitzgerald and Frederick Lloyd.  It was made by Butcher's Film Service at Cricklewood Studios.  It revived a popular character of the silent era, Lieutenant Bob Daring of the Royal Navy who featured in a series of productions made by British and Colonial Films.

The Crimson Circle (1936 film): The Crimson Circle is a 1936 British crime film directed by Reginald Denham and starring Hugh Wakefield, Alfred Drayton, and Niall MacGinnis.  It is based on the 1922 novel "The Crimson Circle" by Edgar Wallace.  It was made by the independent producer Richard Wainwright at Shepperton and Welwyn Studios.

Reginald Denham: Reginald Denham (10 January 1894 – 4 February 1983) was an English writer, theater and film director, actor and film producer.

Justin David Swibel: Justin David Swibel (born April 1, 1983) is an American screenwriter, director, and producer.

The Primrose Path (film): The Primrose Path is a 1934 British romance film directed by Reginald Denham and starring Isobel Elsom, Whitmore Humphries and Max Adrian.  The screenplay concerns a doctor's wife who has to choose between her settled life with her husband in a small town or a more turbulent relationship with a successful artist.  It was based on a play by Joan Temple.

Supporting paragraphs: Reginald Denham Justin David Swibel
Answer: director, and producer