Click on ‘Import & export data’ from the left-hand side menu.
Click on the ‘Products’ menu item.
Click on ‘Product hierarchy’
Click on the ‘Download’ button.
An Excel file containing all your products and the categories that they belong to will be downloaded to your computer.
This list will include both the primary category as well as the additional categories that the product belongs to. You can filter on the ‘Is Primary’ column to switch between the two sets of data.
You can now exit the import & export tool since you do not want to import any data.