Need to add a custom LOV and approve button in Worklist page. What's the possible way?

Oracle EBS

Version: 12.2

We need to add a custom LOV and approve button in Worklist notification page. The requirement is to filter the notification based on the input from LOV and to approve the filtered notification in one shot.

Kindly suggest a possible way whether to modify in the standard page or in the custom page. If in custom, Please mention the steps to follow.

Thanks!