Complex sentence: After three years with Crewe, being the top goalscorer in League Two in his last season, he joined Brentford in 2011 finally gaining promotion to the Football League Championship with the Bees in 2014.
Split into simpler sentences: After three years with Crewe, being the top goalscorer in League Two in his last season, he joined Brentford in 2011. Donaldson spent three years with the Bees before finally gaining promotion to the Football League Championship in 2014.