How to use bootstrap-vue <b-form-checkbox>

Check out example 2 at https://bootstrap-vue.js.org/docs/components/form-checkbox/

Checkboxes – selected values (in this case the user's id) will be elements of the selected array because it's the v-model for the checkbox group. If a user id isn't in the array, it's not selected.

<b-form-group label="Users:">
  <b-form-checkbox-group id="checkbox-group" v-model="selected" name="selectedUsers">
    <b-form-checkbox v-for="(user, index) in users" :value="user.id" switch></b-form-checkbox>
  </b-form-checkbox-group>
</b-form-group>

Your component JS – there are a million ways to find out if a user is selected, below is an example method to see if a specific user id exists in the selected array.

data(){
  return {
    selected: []
  }
},
methods: {
  userIsSelected(userid){
    return this.selected.includes(userid)
  }
}

If you want to know when selection changes, you can watch the selected array:

data(){
  return {
    selected: []
  }
},
watch: {
  selected: {
    deep: true,
    handler: function(newValue){
      console.log("Selected users changed", newValue)
    }
  }
},
methods: {
  userIsSelected(userid){
    return this.selected.includes(userid)
  }
}

The deep property may or may not be necessary, but if your array ever includes objects or nested arrays it would be important.

in case someone's still looking this is what I ended up doing.

if checkbox is ticked the current user object in the loop will be added to the selected [] array and removed when unticked so you can what you want in the changeMethod.

<div>
 <b-form-checkbox
    v-for="(user, index) in users"
    :key="index"
    v-model="selected"
    :value="user"
    name="checkbox"
    @change="changeMethod">
 </b-form-checkbox>
</div>

data(){
  return {
    selected: []
    users: [{
      name: 'user 1'
      id: '1'
     },...]
  }
},

methods: {
//handle what happens to your selected value when checkbox status changes
  changeMethod(){
    console.log(this.selected)
  }
}