i want to display return data to convert json

these my table database in the model sub_bidang

id  id_bidang       name    
1      1            Backend Developer   
2      1            Frontend Developer  
3      2            Senior Marketing

i want to display all the name in the array nama sub bidang by field id bidang

$data = Posting::find($id);

    foreach ($data->sub_bidang as $value) {

        $data = [

            'id posting job' => $data->id_posting_job,
            'id kategori' => $data->id_kategori,
            'nama kategori' => $data->kategori_posting['nama'],
            'id bidang' => $data->id_bidang,
            'nama bidang' => $data->bidang['nama'],
            'nama sub bidang' => [
                'bidang' => $value->nama
            ]  
        ]; 

        return response()->json($data);
    } 

but doesnt work, just display backend developer in the array nama sub bidang. like this

{
  "id posting job": 1,
  "id kategori": 1,
  "nama kategori": "Part Time",
  "id bidang": 1,
  "nama bidang": "IT",
  "nama sub bidang": {
    "bidang": "Backend Developer"
  }
}

there should be display backend developer and frontend developer, what the problem ?

via Chebli Mohamed