Complex sentence: Lega Italiana Calcio Professionistico (Lega Pro) is the name of the professional football league governing the third and fourth highest divisions in Italy: the "Prima Divisione" (third tier) and the "Seconda Divisione" (fourth tier).
Split into simpler sentences: Lega Italiana Calcio Professionistico (Lega Pro) is the name of the third and fourth highest football leagues in Italy. It is broken up into "Prima Divisione" (third tier) and "Seconda Divisione" (fourth tier).