Product Type(s) are located at the top of the library above Designers and the Search Window. In addition to the Product Type name, the number represents the amount of designs within that specific Product Type. See below.

You can select any number of Product Type(s) to sort your designs. For example, you can sort your library by Embroidery only by clicking on the Embroidery product type.

Additionally, you can sort your library by Applique and Embroidery by clicking on both product types individually. See below.

To view All which will unselect all individual product types previously selected, click on All.