I want add logic so that when a user enters a parameter, the reports returns all records equal to that parameter as well as all the children of the parameter. For example, if the user enters the word Hammer, the reports returns all hammer records as well as nails and boards assuming these are already defined as children in the DB table. How can I do this?

There is table.parent_field and a table.child_field defined in the database however the part I am having trouble with is getting the Crystal logic to select the parent field as well as any children field (multiple parameters) IF a child field or fields exist for the parent field. Some of the parents do not have children. Any thought for this?