How to get the lastest record for each day

Hello,
 
I meet a problem in my work in BO web intelligence.
I have a set of data, it look like that, for example:
 
Delivery_Data Forecast_Data Orders
12/16/2015 12/15/2015 10:00:00 AM 100
12/16/2015 12/15/2015 10:30:00 AM 120
12/16/2015 12/15/2015 11:00:00 AM 160
12/13/2015 12/12/2015 10:00:00 AM 300
12/13/2015 12/12/2015 10:30:00 AM 320
12/13/2015 12/12/2015 11:00:00 AM 340
 
So, I do the forecast one day before the deliver data, every half hour, and the 3rd colums is my total orders at the time I am doing the forecast;
 
However,now I only want to return the latest record for each delivery data, so the result should be
12/16/2015 12/15/2015 11:00:00 AM 160
12/13/2015 12/12/2015 11:00:00 AM 340
 
However I can use max to help me return the max forecast time, but the orders measure will aggregate automatically, I use foreach(forcastdate),it doesn;t works, so how can I solve this problem, what function may be useful here;
 
thanks so much