Yii2 Gridview display custom content instead of filter fields

Just set the filter in your column config. Because we don't have additional information about your columns / grid code a simple example. Please add next time some code fragment to your question.

echo GridView::widget([
    'dataProvider' => $dataProvider,
    'filterModel' => $searchModel,
    'columns' => [
        ....
        'room',
        [
           'attribute'=>'room_no',
           'filter'=>'whatever',
        ],
        ...
     ]
   ]);