drill down
phrasal verb with drill verb uk/drɪl/ us/drɪl/
深层探究（通过电脑或网络，将搜索从对象的概要信息向具体信息扩展）
to look for something on a computer or website by moving from general information to more detailed information
Many websites have some form of hyperlink navigation as you drill down. 浏览层层网页时，你会发现很多网页都有超链接导航。