How to create separate action when generating GridView via gii?

Question

Yii

Good afternoon, I'm trying to deal with Yii2 and a question arose. I generated CRUD with a search model and everything works, all data is displayed from the table, all data is filtered, everything is edited as it should, but I would like to split it into separate actions with filtered data output. For example, mail is stored in the database, the generated code displays all of it, but I want to create, for example, 3 separate pages, which would, for example, be displayed by status of an open letter, delivered, etc. How can this be done?