ensuite tu fais une requête serveur mais n'exploite pas le resultat du coup y a peu de chance que cela soit utile ;)
$.ajax({
        type: 'POST',
        url: 'list.php',
        data: 'du='+du+'&au='+au+'&page='+page+'&departement='+dep+'&region='+region+'&loisir='+loisir+'&ville='+vil+'&date='+datetimepicker2,
        processData: true,
        async: false, 
// success , complete, error ????
    });

$sql = 'SELECT * FROM loisirs JOIN `regions` ON `regions`.`region_id` = `loisirs`.`id_region` WHERE  loisirs.date_fin_sortie > NOW() AND loisirs.valide = 1';
	// region
	if(!empty($_REQUEST['region'])){
	  // FIXME : sql injectin spoted
	  $sql .= ' AND regions.url = \''.$_REQUEST['region'].'\'' ;
	}
	if(!empty($_REQUEST['departement'])){
	  $sql .=  ' AND loisirs.id_departements = '.$_REQUEST['departement'];
	}
	
	if(!empty($_REQUEST['loisir']) ){
	  // FIXME : sql injectin spoted
	  $sql .=  ' AND loisirs.genre_loisir = \''.$_REQUEST['loisir'].'\'' ; // loisir
	}
	
	// Recherche par date
	// FIXME : $du et $au n'existe pas ici ;)
	// FIXME : sql injectin spoted
	if(!empty($du) && !empty($au)) {
	  $sql .= ' AND (DATE_FORMAT(loisirs.date_debut_sortie, \'%Y-%m-%d\') <= \''.$du.'\' AND DATE_FORMAT(loisirs.date_fin_sortie, \'%Y-%m-%d\') >= \''.$au.'\')';
	}
	
	 // Recherche par ville
	if(!empty($_REQUEST['ville'])) {
	  $sql .= ' AND loisirs.city = \''. getRealValue($_REQUEST['ville']). '\'';
	}
	
	// Recherche par salle
	if(!empty($_REQUEST['manufacturer'])){
	  $sql .= ' AND loisirs.manufacturer = \''. getRealValue($_REQUEST['manufacturer'] , 'manufacturer') .'\'';
	}

if (empty($_REQUEST['loisir']) && empty($_GET['page']) && empty($_REQUEST['departement'])) {
		$sql .= ' GROUP BY id_type_loisirs ORDER BY loisirs.id_loisirs';
		}else {
		  $sql .= 'ORDER BY loisirs.id_loisirs';
		}
		$sql .= ' DESC LIMIT '.intval(($page-1)*$parPage).', '.$parPage ;
		
		// la première partie de la requête permet de filtrer et de grouper, celle ci d'avoir les données
		$sqlFinal = 'SELECT * FROM loisirs JOIN regions ON regions.region_id = loisirs.id_region WHERE loisirs IN ('.$sql.')';
		
		// $sqlFinal;

<!-- Nav filtre Rapide -->
<nav class="navbar_filter navbar-default">
    <div class="container">
        <div class="filter-tabs">
        <div class="navbar-header">
        <button type="button" class="navbar-toggle collapsed pull-left" data-toggle="collapse" data-target="#nav-secondary" aria-expanded="false" aria-controls="navbar">
        <span class="sr-only pink_filter">Toggle navigation</span>
        FILTRE RAPIDE <i class="fa fa-clock-o"></i>
        </button>       
        </div>
        
        <!-- Filtre rapide -->
        <div id="nav-secondary" class="navbar-collapse collapse">
        <ul class="nav navbar-nav time">
        <li class="active"><a href="#home" data-du="" data-au="" data-page="1" data-toggle="tab" >Toutes </a></li>
        <li><a href="#profile" data-du="<?php echo date('Y-m-d'); ?>" data-au="<?php echo date('Y-m-d'); ?>" data-page="1" data-toggle="tab">Aujourd'hui </a></li>
        <li><a href="#messages" data-du="<?php echo date('Y-m-d', strtotime('+1 day')); ?>" data-au="<?php echo date('Y-m-d', strtotime('+1 day')); ?>" data-page="1" data-toggle="tab">Demain </a></li>
        <li><a href="#settings" data-du="<?php $strtotime = (date('N') == 7) ? 'Saturday - '.date('N').' days' : 'Saturday'; echo date('Y-m-d', strtotime($strtotime)); ?>" data-au="<?php echo date('Y-m-d', strtotime('Sunday')); ?>" data-page="1" data-toggle="tab">Ce week end </a></li>              
        </ul>
        </div>
        <!-- End Filtre rapide -->
        </div>
	</div>
</nav>
<!-- End nav -->