How do you set a default cost center and/or internal order per business area through OKB9?

How do you set a default cost center and/or internal order per business area through OKB9?

On 4.6x and above enter the cocd and account and select the account assignment detail field as 2 (Business area is mandatory).

Select the line you just entered and click on the left side of your screen "detail per business area/valuation area".