如何在2个谓词和2个表上进行LINQ左连接？

public class TableA
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public class TableB
{
    public int Id { get; set; }
    public string Description { get; set; }
}

List<TableA> tableA = new List<TableA>
{
    new TableA { Id = 1, Name = "Item1" },
    new TableA { Id = 2, Name = "Item2" },
    new TableA { Id = 3, Name = "Item3" }
};

List<TableB> tableB = new List<TableB>
{
    new TableB { Id = 1, Description = "Desc1" },
    new TableB { Id = 2, Description = "Desc2" }
};

var leftJoinResult = from a in tableA
                     join b in tableB on a.Id equals b.Id into bGroup
                     from b in bGroup.DefaultIfEmpty()
                     select new
                     {
                         Id = a.Id,
                         Name = a.Name,
                         Description = b?.Description
                     };

foreach (var item in leftJoinResult)
{
    Console.WriteLine($"Id: {item.Id}, Name: {item.Name}, Description: {item.Description ?? "N/A"}");
}

Id: 1, Name: Item1, Description: Desc1
Id: 2, Name: Item2, Description: Desc2
Id: 3, Name: Item3, Description: N/A