Company,cost centres(branches) and department under branches

Hi All,
Here is my issue, I wanna create a Company with 3 Branches (cost centres) and Under these Branches I wanna setup 3 Divisions/Departments each. When creating a Department I cant see any option of assigning it to a Branch (Cost Centre). How can I solve this Issue

what’s the reason stopping you from creating branches as group cost centers, and department as non group cost center?