var query = categoria.split(",");
var arr = [];
    $.each(query, function(index, value){
        var querySearch = value.toLowerCase();
        var semalhantes = Object.values(dados).filter(function(objecto) {
            return objecto.categoria.toLowerCase().indexOf(querySearch) > -1
        });
        arr.push(semelhantes);
    });

$arr = explode(', ', $categorias);
    foreach($arr as $src){
            $cat_search[$src] = array_keys(
                        array_filter(
                            $titulos,
                            function ($value) use ($src) {
                                return (stripos($value['categoria'], $src) !== false);
                            }
                        )
            );
    }
    $merged[$obj] = call_user_func_array('array_merge', $cat_search);
    $unique[$obj] = array_unique($merged[$obj]);