For me, either "focused" or "focusing" is correct. For the second, I would use "of'.
Interested in Language
I am not sure if the word "focus" should be "focused" or "focusing" in the following context. And, should I use "on" or "of" or other preposition for "knowledge"?
Based in Shanghai, Holden is heading the Hong Kong investment team focused/focusing on the Hong Kong equity strategy. Holden has 20 years of industry experience and brings significant local knowledge on/of/in Hong Kong markets to the company.