[Vuejs]-How to remove object from v-model array when field in the object has changed

your user is an array, and your select is set to model user.level. What this does is putting a property level onto the array. What you want is to do that to individual object inside that array.

What you are missing is a v-for

<div v-for="_user in user">
    <input type="checkbox" v-model="_user" :value="{ name: displayName, email: userEmail, level: '' }" />
    <select v-model="_user.level">
      <option value="low"> Low </option>
      <option value="middle"> Middle </option>
      <option value="high"> High </option>
    </select>
  </div>

should probably name the array of user users though.