narrow something down
phrasal verb with narrow verb uk/ˈnær.əʊ/ us/ˈner.oʊ/
C2 把…缩减，压缩
to make a number or list of things smaller, by removing the things that are least important, necessary, or suitable
We narrowed the list of candidates down from ten to three. 我们把候选人从10位筛选至3位。