narrow down
To pare the number of people or things on a list down to a more manageable or select number. A noun or pronoun can be used between "narrow" and "down." We've narrowed down our list of candidates to just three, but it's going to be nigh impossible to choose from them. Let's narrow it down to just our very top choices, otherwise we'll never pick a place to go.
narrow something down (to people or things)
to reduce a list of possibilities from many to a selected few. We can narrow the choice down to green or red. We narrowed down the choice to you or Paul.