你可以使用Laravel的DB::select查询。然后传递客户端id、月账单日期和年账单日期的参数，然后执行查询。

$query = "
SELECT *
FROM payment_new
WHERE Client_Id = IFNULL(NULLIF(trim(?), ''), Client_Id)
    AND MONTH(Bill_Date) = IFNULL(NULLIF(trim(?), ''), MONTH(Bill_Date))
    AND YEAR(Bill_Date) = IFNULL(NULLIF(trim(?), ''), YEAR(Bill_Date))
ORDER BY SNo DESC
LIMIT 1
";

$params = ['1','05','2023'];
$result = DB::select($query, $params);

希望这能解决你的问题。
通过使用雄辩：

$params = ['1', '05', '2023'];
$result = Payment::where('Client_Id', '=', DB::raw("IFNULL(NULLIF(trim(?), ''), Client_Id)"), $para[0])
->whereMonth('Bill_Date', '=', DB::raw("IFNULL(NULLIF(trim(?), ''), MONTH(Bill_Date))"), $para[1])
->whereYear('Bill_Date', '=', DB::raw("IFNULL(NULLIF(trim(?), ''), YEAR(Bill_Date))"), $para[2])
->orderBy('SNo', 'desc')
->limit(1)
->get();