From the Items screen, you can export all or specific Product Recipes / BOM to a CSV file.
You can then use that file to make changes to your Product recipes in bulk by editing the file and importing the Recipes back into Katana. Read more about updating Product recipes in bulk
To export Product recipes:
Navigate to the Items screen.
Check the products that you want to export the Product recipe for.
Select Bulk actions.
In the drop-down menu, select Recipes / BOMS under Export.
To export all your Product recipes, deselect any products and click Bulk actions > Recipes / BOMs.