如何执行此输入为下拉按钮

Question

我该如何在bootstrap中作为下拉按钮输入

<div class="form-group">
  <label class="col-md-4 control-label" for="user_type">Tipi userit</label>
  <div class="col-md-8">
    <input id="user_type" name="user_type" type="text" placeholder="Tipi i Userit Admin/Editor/User" class="form-control input-md" value="{{ old('user_type') }}" required> 
    @if ($errors->has('user_type'))
      <span class="help-block">
        <strong>{{ $errors->first('user_type') }}</strong>
      </span> 
    @endif
  </div>
</div>