Complex sentence: With the advent of talkies, Boylan entered into the arena of screenwriting in which he worked primarily as a script doctor, mainly contributing dialogue, first at Fox and later at Columbia as well as at other studiios such as Disney.
Split into simpler sentences: With the advent of talkies, Boylan entered into the arena of screenwriting in which he worked primarily as a script doctor. Boylan's work was later expanded to Columbia as well as at other studiios such as Disney.