There are two ways to track/view inventory for each product/variant amongst multiple locations/warehouses.
1. Go to Reports > Location Reports > click on "Manage Filters" and fill in parameters as desired and click "Run" or select "All" under warehouse only and leave other fields blank and click "Run".
2. At the top right of the screen select "All" for warehouse selection then go to Inventory > View Variants > search or scroll through the list and click on the blue highlighted "On Hand" number to see a popup window with inventory numbers. Additionally, you can click to open a variant and toggle to "Inventory" tab to see the inventory numbers.