Similar to the case of scanning barcode, you can select any product in the system to adjust stock, including those not assigned to the selected warehouse.
If you have any trouble finding the product on the list, you can always use the filter to minimize your effort.
Option 3: Import product(s) from a CSV file
Finally, if you prefer mass adjustment for many SKUs at a time, you can simply import a CSV file to the system. You can execute stock adjustment immediately, or just upload the CSV file for further adjustment.
What sets Magestore Solution apart from the core Magento feature? Our solution allows you to record the history of the adjustment. In addition, you can download a list of invalid SKU in case you have some errors in your CSV file. With this list, you can skip the exhausting process of going through the entire product list to identify the error(s).