plugins - Adding a Taxonomy Filter to Admin List for a Custom Post Type? - WordPress Development Stack Exchange
Blog Filter – Advanced Post Filtering with Categories Or Tags, Post Portfolio Gallery, Blog Design Template, Post Layout – WordPress plugin | WordPress.org
Ultimate Guide to WordPress Post and Page Filtering
How to Use Categories and Tags for Pages in WordPress - GreenGeeks
What is a search facet? What is a search filter?
How to Let Users Filter Posts and Pages in WordPress