With Attributes Filter widget you can filter your product listing by any attribute. To enable product filtering to to Appearance > Widgets and fine the Attributes Filter widget.
Once the widget is placed in your favourite sidebar (e.g. Product Filters Bar) it will show filter drop-downs for all selected attributes.
Select Filter Attributes
You can select which attributes will show up as filters in the Enable for field.
Please note that if any of the products currently listed on the screen do not have any of the attributes available the drop-down will not show up. The attributes values are also limited to those available in current product listing.
E.g. if you are viewing the main product listing all attribute values will be available, however if you go to the category page which has only a couple of products the filter drop-down will show only the attributes assigned for the products currently available.