how to assign the same item in three or four different warehouse
In Manager, you can receive items or deliver items from one Inventory location per transaction.
You cannot receive into different location in one transaction(one Goods receipt Note) or deliver from different locations in one transaction (one Goods Delivered Note). Meaning even if inventory received/delivered will be distributed to different locations, you will have to receive/deliver them at one location first before you transfer them to their various locations using inventory transfer. Or, issue different delivery notes or receipt notes with the various locations involved.