HP Intelligent Management Center Standard Software Platform - Manual (Page 611)

The program automatically expands the Value list. You use this area to
define the fields that make up your cascading list of values. This example
uses a cascade of Country, Region, and City.
9. From the Value list, select Country.
10. Click the blank field under Country and select Region.
11. Click the blank field under Region and select City.
12. In the Parameters area, click City to bind the field that contains the City
value to the parameter.
In this step, you are choosing the field in your cascading hierarchy that
should be bound to the parameter field that you are creating. Because
this particular parameter is intended to provide Crystal Reports with a city
value, you bind the parameter to City.
13. In the Prompt Text field (in the Value Options area), enter additional
prompting text for each of the fields in your cascading list of values.
This is the text that appears in the "Enter prompt values" dialog box when
the report is refreshed.
Crystal Reports 2008 SP3 User's Guide 611
23 Parameter Fields and Prompts
Creating a parameter with a cascading list of values