how to save selected checkbox value in database instead of true false in Angular 4

Here I have some checkbox and I want to save their data value not ture and false to server. If I click on checkbox then I am pushing group id in array and that group id I want to save in database.

This is the My Html Code:

<input type="checkbox" value="group._id" formControlName="group_id" formControlName="group_id"(change)="getCheckboxValues($event,group)" /><span innerHTML=""></span>

This is my ts file code goes here : here I am pushing only group id

getCheckboxValues(event,id){

    debugger;
    const checked = event.target.checked;
if (checked) {
    debugger
 this.selectedGroups.push(id._id ); // push the Id in array if checked
  } else {
      debugger
  const index = this.selectedGroups.findIndex(list => list.user_id == id);//Find the index of stored id
  this.selectedGroups.splice(index, 1); // Then remove
}

}

    // World View Question
worldViewQuestion = function (data) {
    debugger;
//  const videodisplaygroup =this.selectedGroups;

    if (this.worldViewForm.valid)

        data.group_id = $('input[name=group_id]:checked').val();



    $("#worldView").val("SAVING...").attr("disabled", true);
    this.authService.SaveWorldViewQuestion(data).subscribe(data => {
        debugger;
        if (data.success) {
            //console.log({...this.worldViewForm.value,videodisplaygroup})
            $.growl.notice({
                title: 'Success',
                message: data.message
            });
        } else {
            $.growl.error({
                title: 'Error',
                message: data.error
            });
        }
        $("#worldView").val("SAVE").attr("disabled", false);
    });
}

I want to save group id in videodisplaygroup this is my data structure here is the videodisplaygroup parameter where I want to store value

Please your help would be great