Can I place the same product in two categories in my Facebook Shop with ShopTab?

You can place the same product in multiple categories. The best way to see this is demonstrated in a CSV file noted below but can be done manually as well.

To do this, use the same information in the title, description, link, image_link, price and condition (every field but the category field) and create a new product listing. Use a new category name for this product (highlighted below)  and it will show in both category locations in your Facebook store.