Changing the GL code to match what site id you pull from

Hello

I was wondering if anyone knew of a faster way to automatically change the GL Inventory code to correspond with what SITE ID you pull from.

Basically we have 3 separate Site ID that I invoice out of.  When I change it from our default site id I have to physically go into each line item and change the gl code to match with that site id.  I have added a picture for reference.  Is there a way to have it automatically change?

Thank you,

Katie