Generate Item Code Based On Custom Logic

You can make the new Item Code from other fields just before the Item is saved.

A developer adds the script in Desk's Client Script. Search Desk for Client Script, make a new one, and choose Item as its DocType. See Client Scripts for how a Client Script is made and saved.

The script clears the Item Code and builds it again each time the Item is saved. The first two characters come from the Item Group. For example, Test A gives TA and Test B gives TB, and any other group gives XX. The next two characters come from the Brand. For example, Brand A gives BA and Brand B gives BB, and any other brand gives BX.