Check the following link:
https://www.mconnectmedia.com/blog/magento-2-0-tutorial-how-to-add-and-manage-configurable-products/
For Filterable Attribute :
Go -> Stores->Attribute ->Product
Choose Which Attribute you Want to Filterable : Click On Edit
ATTRIBUTE INFORMATION ->Properties Under :
Advanced Attribute Properties
->Use in Filter Options : yes
Hope this might solve your problem.
Regards
Manish
OpenSource Expert | OpenSource Technologies | www.opensourcetechnologies.com
Magento plugins released: http://www.opensourcetechnologies.com/product/product-category/magento-extensions