Hi Brian,
Thanks a lot for you reply, I have tried below but still it's not working.
SELECT mydata.L1, mydata.L2, mydata.Retx, mydata.Prd, mydata.[As of Date], Avg(mydata.Amt) AS AvgOfAmt
FROM mydata
GROUP BY mydata.L1, mydata.L2, mydata.Retx, mydata.Prd, mydata.[As of Date]
HAVING...