<input id="search" />

<div>
  <div class="child">foo</div>
  <div class="child">bar</div>
  ....
</div>

var filterChildren = function() {
    var value = $(this).val().toLowerCase();
    $(".child").filter(function() {
      $(this).toggle($(this).text().toLowerCase().indexOf(value) > -1);
    });
  };

  $("#search").on("keyup", _.debounce(filterChildren, 300));

$(document).ready(function(){
  var map = {};
  $('.child').each(function(i,el){
    map[$(el).text().toLowerCase()] = $(el);
  });
  $('.child').toggle(false);
  $('#search').on('keyup', function(){
    $('.child').toggle(false);
    var el = map[$(this).val().toLowerCase()];
    if (el)
      $(el).toggle(true);
  });
});

$("#search").on("keyup", _.debounce(filterChildren, 300));

function debounce( fn, threshold ) {
    var timeout;
    return function debounced() {
        if ( timeout ) {
            clearTimeout( timeout );
        }
        function delayed() {
            fn();
            timeout = null;
        }
        timeout = setTimeout( delayed, threshold || 100 );
    };
}