这个where 是什么用法啊,

题目

这个where 是什么用法啊,
I can’t think of a single search I’ve done where a board has not instructed me to look at sitting CEOs first.

答案

where引导的是定语从句,修饰的先行词是search.
这个句子中,search有两个定语从句：（which/that) I' ve done和where a board has not instructed me to look at sitting CEOs first.