Query fn_dblog() for the list of Operation in active transaction of the current session
declare @xactid bigint
declare @transactionid nvarchar(28)
select @xactid = transaction_id from sys.dm_tran_current_transaction
select @transactionid = [transaction id] from fn_dblog(null,null) where [Xact ID] = @xactid
select * from fn_dblog(null,null) where [Transaction ID] = @transactionid
The [Xact ID] introduced in SQL Server 2008 has the transaction id for the operation LOP_BEGIN_XACT and all the transaction occuring in its context share the common transaction with the [transaction id] column