Details Parameter
If a grouping template (Templates tab of the data composition schema wizard) specifies Parameter or Template in the Filling property for a properties palette cell and the Detail Parameter specifies the name, the Template Parameters section will have a line added to describe the parameter. The Expression column displays the expression value.
To modify the expression value, switch to the edit mode and in the Expression cell click the selection button. The details parameter editor is opened.
The Add button opens the field selection dialog. Next, the new field is added to the list. Use the Expression column to specify the expression using the data composition system expression language.
From the Primary Action field, select the main details option.
To complete editing, click OK.