When did the nationalist communist alliance split? what did the communists do after the split?

According to an article from countrystudies.us:

"In early 1927 the Guomindang-CCP rivalry led to a split in the revolutionary ranks. The CCP and the left wing of the Guomindang had decided to move the seat of the Nationalist government from Guangzhou to Wuhan. But Chiang, whose Northern Expedition was proving successful, set his forces to destroying the Shanghai CCP apparatus and established an anti-Communist government at Nanjing in April 1927. There now were three capitals in China: the internationally recognized warlord regime in Beijing; the Communist and left-wing Guomindang regime at Wuhan; and the right-wing civilian-military regime at Nanjing, which would remain the Nationalist capital for the next decade."

The answer is professionals such as attorneys.