title: OCTOBERCMS Dropdown options dependent on selected value on other dropdown
body: <p>I'm stuck with this problem and i can't figure out how to solve after some time searching for a example.</p>
  
  <p>The two dropdowns options are table dependent on their values.</p>
  
  <p>I have the one table with 'area' values (nested with simple tree working ok) with the following structure on fields.yaml file:</p>
  
  <pre><code>fields:
    id:
      label: Número
      oc.commentPosition: ''
      span: auto
      disabled: 1
      type: number
  
    area_id:
      label: 'Parente de'
      oc.commentPosition: ''
      emptyOption: 'Sem valor'
      span: auto
      type: dropdown
  
    area:
      label: Área
      oc.commentPosition: ''
      span: full
      required: 1
      type: text
  </code></pre>
  
  <p>I also have another table 'modulos' values with the following structure in fields.yaml:</p>
  
  <pre><code>fields:
    modulo:
      label: Módulo
      oc.commentPosition: ''
      span: auto
      required: 1
      type: text
  
    area:
      label: Área
      oc.commentPosition: ''
      nameFrom: area
      emptyOption: 'Sem valor'
      span: auto
      descriptionFrom: id
      type: relation
  </code></pre>
  
  <p>In the 'Area' model I have:</p>
  
  <pre><code> ... 
   public $hasMany = [
      'modulos' =&gt; ['JML\Gkb\Models\Modulos']
   ];
  </code></pre>
  
  <p>In the 'Modulos' model I have</p>
  
  <pre><code>....
   public $belongsTo = [
      'area' =&gt; ['\JML\Gkb\Models\Area']
  ];
  </code></pre>
  
  <p>I have other model that have relations with previous fields and two dropdown fields working ok without any filter, and the troubleshoting field (modulos) where I can't find a way to filter based on the values of 'Area' dropdown I have the following in fields.yaml.</p>
  
  <pre><code>....
  modulo_id:
    label: mod
    oc.commentPosition: ''
    emptyOption: 'Sem valor'
    span: auto
    required: 1
    dependsOn:
  
  area
    type: dropdown
    tab: Geral
  </code></pre>
  
  <p>In my models PHP file where I have the dropdowns defined, I have:</p>
  
  <pre><code>public function getModuloIdOptions() {
      return Modulos::where('area_id', '=', $this-&gt;area)-&gt;lists('modulo', 'id');
  }
  </code></pre>
  
  <p>That to me seems logical (maybe not) and I tried with DB also and many more other. I tried with <code>dd()</code> to see if I can get the values from the first dropdown to no avail. If I try to filter the values, no value appears at all (except an empty value).</p>
  
  <p>Any help out there ???</p>
  
  <p>TIA</p>
  
  <p>JL</p>