Display children account's assets on parent account

Hello, I am using the Customer Assets feature in Dynamics CRM. Currently, Assets are being created within a contact (if the asset is specific to that contact, like a laptop) or at the Account level (for things like Printers that don't correspond to an individual contact). I then have the Customer Assets subgrid set up to display all assets, whether they are associated with the Contact or the Account. This is working well for most accounts, however I have some accounts where there is a need to use the "parent" account feature with multiple "children" accounts. I am using the "Parent Account" native functionality in Dynamics to create this relationship, which works, however I need all Customer Assets that exist in the children accounts to be visible in the same Customer Assets subgrid on the parent account. In other words, I have parent account "A" and children accounts "B", "C", and "D". Customer Assets are working great when viewing the Customer Asset subgrid in accounts B, C, or D. But, when I view the Parent Account A, the Customer Asset subgrid is blank, and I want it to show all Customer Assets at children accounts B, C, and D. 

Any input is appreciated. Thanks in advance!