の一番上

the very top of; eldest

→ の
phrase Rare #29,241
the very top of; eldest Used for the highest part of something, and with family members it means the oldest or eldest. The particle の links it to the preceding noun, as in 棚の一番上 (the very top of the shelf) or 私の一番上の兄 (my eldest brother).
JA: 荷物は棚の一番上に置いてください。
EN: Please put the luggage on the very top shelf.

僕はトムの一番上の息子なんです

I'm Tom's eldest son.

うちの家の一番上にあるんです

Our house is right at the top of the hill.

タンスの一番上入れといて

Put it in the top drawer.

私の名前がリストの一番上にあったため私が最初にオフィスに入るように呼ばれた

Because my name was at the top of the list, I was called in to the office first.