HP Intelligent Management Center Standard Software Platform - Manual (Page 609)

Note:
If you don't want to see the parameter field you dropped in your report,
place it in a section you can suppress, such as a report header or footer.
When you look at your dynamic prompt within Crystal Reports, it does not
seem to be much different from a static prompt. In the background, however,
Crystal Reports stores the information about the list of values that you created
for this prompt. When the report engine requires a parameter that has a
dynamic prompt, it will access the data source and populate the list of values
automatically. This will be displayed on the end user prompt page. If you
choose to publish the report to BusinessObjects Enterprise or Crystal Reports
Server, the list of values becomes a separate entity that you can optionally
schedule in Business Views Manager.
Creating a parameter with a cascading list
of values
A dynamic prompt can include a cascading list of values, which adds
additional levels of selection for your users. For example, if you are prompting
for a city value, but you also need to know which country and region that city
comes from, you could create a dynamic and cascading prompt. In this case,
you first prompt for a country, and when that value has been selected, the
program prompts for a region by showing only the regions that apply to the
selected country. Finally, when a region value has been selected, the program
prompts for a city by showing only the cities that apply to the selected region.
In this way, you can be sure that your user picks the correct city (for instance,
Vancouver, Washington, USA rather than Vancouver, British Columbia,
Canada).
As with a dynamic prompt that has only one value, you are able to create or
specify a cascading list of values that you can schedule for updates as often
as you like through the Business View Manager. For more information about
scheduling a list of values, see the Business Views Administrator's Guide.
Use the following steps to create a parameter that uses a dynamic prompt
and a cascading list of values.
Crystal Reports 2008 SP3 User's Guide 609
23 Parameter Fields and Prompts
Creating a parameter with a cascading list of values