〜のなかで〜がいちばん
The most … in a group (superlative)machine translation
FormationNoun (group) + のなかで + noun + がいちばん + adjective
To say "the most … in a group", use the frame: group + のなかで + X + がいちばん + adjective. いちばん literally means "number one".
To ask "what / who / where is the most …", use a question word + がいちばん: スポーツのなかで、なにがいちばんおもしろいですか — among sports, which is the most interesting?
As with the comparative, the adjective keeps its form — just add いちばん in front to get the meaning "most".
Examples
家族の中で、母がいちばん早く起きます。
In my family, my mother gets up the earliest.
スポーツの中で、サッカーがいちばん好きです。
Among sports, I like soccer the best.
一年の中で、八月がいちばん暑いです。
In the year, August is the hottest month.