Parent Project to Sub project

Hello everyone, I need some help please!

Is it possible for SF to automatically reduce the gross amount in a "Parent Project" once a sub project has been created for certain amount? for example, the parent project gross amount initially entered in SF was 5,000 and a few days after i created a sub project to the parent project, and bill the sub project for 3,000, can SF recue the parent project amount to $2,000 once the sub project is billed?

if so, how do i get this done?

#Nonprofit

Thanks so much!

Mila