Complex sentence: Josh performed well at the 2015 Australian Swimming Championships, placing 3rd in the Men's 50m Freestyle Multi-Class; 2nd in the 100m Freestyle; and 3rd in the 200m Freestyle.
Split into simpler sentences: Josh performed well at the 2015 Australian Swimming Championships. He placed 3rd in the Men's 50m Freestyle Multi-Class; 2nd in the 100m Freestyle; and 3rd in the 200m Freestyle.