In this example, we will be using the Orders table in the Northwind database in SQL Server.  The crystal report will display the last order date for each customer ID. 

1. You need to group the report by customer id by using Group Expert and selecting the Orders.CustomerID field
2. For the OrderDate, goto select expert
3. Click on Show Formula >>> button
4. Select Group Selection radio button
5. Enter the following formula: {Orders.OrderDate} = Maximum ({Orders.OrderDate}, {Orders.CustomerID})
6. Click OK button to close the Select Expert window

Now your report should be show the latest order date for each customer.