Complex sentence: Ross served under U.S. President Bill Clinton on the board of the U.S.-Russia Investment Fund, and later, under New York City Mayor Rudy Giuliani as the Mayor's privatization advisor.
Split into simpler sentences: Ross served under U.S. President Bill Clinton on the board of the U.S.-Russia Investment Fund. Later, under New York City Mayor Rudy Giuliani, Ross served as the Mayor's privatization advisor.