You can't query by populate.

But you can implement that instead:

1. First find Area by nombre_area
2. And then find Users with areaI equal to that area id

It's simple and should be performant, as I believe you don't have thousands of areas.

you have two solutions

1- separate the query and write a method & named it aeraExist(name) and filter it by name

2- in the populate add match & if that filter doesn't match it will return null

    .populate({
      path: "areaI",
      match: {name: "Us"},
    })