"It's the area that I have the least knowledge in."
"It's my weakest area."
"It's the area that I have the least knowledge in."
"It's the area that ~" 「〜分野です」
"I have the least knowledge" 「最も知見がない」
"least" 「最も」
"knowledge" 「知見」"experience" も言えます。
"It's my weakest area." 「わたしの一番弱い分野です」
"I would like to focus on overseas expansion as it is the area that I have the least experience in."
「海外展開は自分にとって最も知見がない分野なので、重点的に学習したいです」
オーストラリア 
