Related List on Member Accounts Roll Up to the Parent Account

I have a related list that shows on the account (Machines Installed at Location, for Example "Zoho - Austin, TX" and "Zoho - Plesanton, CA") ... but I would also like the related list to roll up to the parent account as well (for example, "Zoho - Parent") which is a container for the two member account locations.

So I can see ALL machines installed for the Parent/Global company. Is this not possible? I tried adding an additional lookup field for "parent account" and that works, but now you have two related lists that are about the same - and I do not want them shown. Maybe I can hide the Member account list on the Parent Account and hide the Parent Account list on the Member Accounts???

I was just hoping there would be an easy way to see this similar to how all Notes roll up from Contacts to the Account.