Hi,
have you looked into this step-by-step in the documentation of creating a custom filter?
docs.kentico.com/.../developing-custom-filters
This also includes the part where you register your filter: 'Adding the filter to a portal engine page'
You use a Kentico Filter Web Part and point it to your custom file
![Image Text](https://content.screencast.com/users/DavidTK/folders/Jing/media/ef3aa0c9-3907-4a54-b8c2-734df75402b9/2018-01-29_1049.png)
You could also create your own Filter Web Part, you might want to look in the Dancing Goat sample site to see Kentico samples.