Complex sentence: Fiorina spent two years leading the Central Intelligence Agency's External Advisory Board, from 2007 to 2009, and became chairman of that board, when the board was first created in 2007 by then-CIA director Michael Hayden during the George W. Bush administration.
Split into simpler sentences: Fiorina spent two years leading the Central Intelligence Agency's External Advisory Board, from 2007 to 2009. Fiorina became chairman of that board, when the board was first created in 2007 by then-CIA director Michael Hayden, during the George W. Bush administration.