The phrase "in which role" is correct and usable in written English.
It is used when referring to a particular role or capacity that a person is playing or has been assigned. Example: The new hire was uncertain of his duties at the company, so his supervisor outlined the responsibilities of his position in which role he was expected to fulfill.
By 1077 he had assumed the title imperator totius Hispaniae, in which role other Christian kings accepted him.
Joyce Arram writes: In 2002 Tony Newton joined the trustees of the National Benevolent Fund for the Aged (NBFA), in which role he was both enthusiastic and involved.
He also has a best-buddy-cum-wing-man in the form of a soldier called Rhodey, in which role Terrence Howard is performing at about 35% strength.
But Theresa May decided to keep her friends close and her enemies closer by appointing him international trade minister, in which role he has done nothing.
Le Chiffre is played by Mads Mikkelsen, in which role he has the privilege of following Orson Welles from the 1967 spoof version.
Vince Cable, the Lib Dems' Treasury spokesman, becomes business secretary, in which role his anti-bank and anti-business rhetoric may give rise to some unhappiness.
Dance is an oral tradition in which roles and works are passed one from one generation to the next.
And, maybe, some more films in which roles that couldn't be played by men because they are too vulnerable and too feminized are played by men anyway.
In a triumph of form, pacing and power, the author brings Dwight and Ethan to a meeting in which roles are reversed and anything is possible: Violence.
However, shamanism is also used more generally to describe indigenous groups in which roles such as healer, religious leader, counselor, and councillor are combined.
Scientists have long been fascinated by the complexity of the hives and their elaborate division of labor, in which roles are assigned ranging from queen to, in essence, undertaker.
