Create a calculated column with different granularity

Hi all, right now I'm working on SAP HANA studio 2.3.41

I am trying to create a new calculated column within a model, but with lower granularity.

Suppose the table has 10 fields as follow:

CUSTOMER_ID, MOVEMENT_DIRECTION, SHIPMENT_NUM, HEADER_TYPE, SOURCE_ID, DESTINATION_ID, LEAD_TIME, SHIPPING_DATE, ACTUAL_COST, SHIPPING_QTY

I want to create a new calculated column called AVERAGE_RATE with this expression

"ACTUAL_COST"/"SHIPPING_QTY"

However, I need to create the calculated column at the granularity of just MOVEMENT_DIRECTION, HEADER_TYPE, LEAD_TIME.

Any suggestions on how to accomplish this?