at the top of the tree （在行业、事业中）高居首位，处于顶峰，登峰造极

【例句】
Mike is at the top of the tree as a lawyer.
作为律师，迈克的事业达到了登峰造极的地步。

Oddly, he remarked, he had never felt "more secure, more certain of myself" , than when he was in the White House, at the top of the tree.
奇怪地是，与过去他在权力巅峰——再白宫时相比，现在的他，感受到从未有过的安全感和自我肯定。