source: inuyasha anime gif | WiffleGif

with object (sniff something out) informal discover something by investigation:

〈警察犬などが〉〈爆発物･麻薬など〉を(においをかいで)見つける(out); ｟くだけて｠ 〈情報･秘密など〉をかぎつける, 見つけだす(out)

e.g. he made millions upon millions sniffing out tax loopholes for companies.