How to mass update Req BU using "auto site assignement" tab in the supplier site level ?

Summary:

Hello,

We have 2 proc BU (one for each country) and many Req BU, we will add more than 200 Req BU to the system and we are looking for the best way to add all these new Req BU to the site assignement ?

Content (required):

We have a shared service model where in 50 Req BUs will be managed by one procurement BU. As we setup this design we noticed that everytime a new Req BU is created, we have to come to the "Site Assignment" tab and Auto Generate it again.

Is there an option where any time we add a Req BU it auto creates it in all sites as well ?