Report of COA question

R12.1

We are doing a new implementation and have our chart of accounts set up to have children and parents and then some 'grandparents' that have parent accounts as their children.  I am looking for a report that will show me what parents roll up under what grandparents.  I found one report but it shows me all of the child accounts that roll up under the grandparents.  Any help would be greatly appreciated.