As for me, I need to better understand what you mean by parent and child fields from the 'same' table. The following is offered as a basic guess...based on a business name and invoice concept.
For example, you need a report needs to show all invoices for each company name, you can use CR grouping. (company name is the parent and invoices are the children)
You would group by company name (Insert group and then select datafield for company name) and then list the invoice information in the details section.
This is all pretty basic stuff and your needs may be more complex. My apologies if I missed the mark.
Regards,
John W.