Default filters allow you to select products based on category, promo price (products containing sale_price data) and ID. However, if you're willing to select products based on a value in Custom Label, you can also do that!
Select the design of your choice.
Under Filters section on the far right side click on "+ Add Filter".
Select the Custom Label where you have the values you want to sort your products by.
Paste in the value.
And that's it! From now on, your design will only apply to products that contain the given value in Custom Label element.