After making a name for himself playing village football, Semmy played for Besta United PNG of the Papua New Guinea National Soccer League for two seasons beginning in 2013. In 2015, he moved to defending league champions Hekari United and appeared for the club during the 2014–15 OFC Champions League, including in a match against Vanuatu's Tafea in which he scored a goal after an individual effort. He scored again against Tefana in a 3–2 victory in the team's final group stage match. Semmy's two goals were enough to place him tied for fourth place in the scoring charts for the final stages of the tournament. He also played for the club in the 2016 OFC Champions League, scoring two goals in three matches of the group stage. His goals came against AS Lössi of New Caledonia and Suva of Fiji.