The Product Matrix shipping extension can filter on the warehouse the item is coming from in addition to the other filters.
You will need the Dropship extension is installed in order to use this.
How to configure the Admin Settings.
You will need to first need to make sure that the Dropship extension is enabled.
In the Shipping Methods under Product Matrix you need the select “Use with Dropship warehouse” and then save this.
NB: The configuration will need to be saved with this option selected prior to uploading a CSV.
How to configure the CSV File.
The “Warehouse ID” column is the ID of the warehouse from Shipping Mgr > Manage Warehouses, as illustrated below.
The CSV file should look like the one below.