相关 select2 from to

if($('.select').length){
  $('.select').select2({
    tags: true,
    placeholder: function(){
      if($(this).data('placeholder')){
        $(this).data('placeholder');
      }
    }
  });
  
  
  $('.select-from').change(function(){
    var selecteId = $(this).select2('val'); 
    
    var x = parseInt(selecteId)+1;
    
    console.log(x);
    
    $('.select-to').select2('val', '' +x );
    
    for(var i = 0; i <= selecteId; i++){
      $('.select-to').find('option:nth-of-type('+i+')').prop("disabled", true);
      $('.select-to').select2();
    }
  });
}

<script src="https://code.jquery.com/jquery-2.2.4.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.7/css/select2.min.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.7/js/select2.min.js"></script>
  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" >
  
  <div class="container">
    <div class="filter-col filter-col_room">
      <span class="filter-text d-block mb-4">
        Кол-во спален
      </span>

      <div class="d-flex align-items-center">
        <span class="filter-col__label mr-2">
          от
        </span>
        <select name="catalog-filter-from" class="select select-from" id="count-room-from">
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
          <option value="4">4</option>
          <option value="5">5</option>
        </select>
        <span class="filter-col__label ml-4 mr-2">
          до
        </span>
        <select name="catalog-filter-to" class="select select-to" id="count-room-to">
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
          <option value="4">4</option>
          <option value="5">5</option>
        </select>
      </div>
    </div>
  </div>