Route_option and listview


I am making a new doctype (Project and Task) using dashboard and filtering related documents.
I have managed to make all parts working, displaying dashboard, showing the badge count and having the list view of the related document filtered if clicked from the dashboard.
The problem is when I view the tasks connected to one project the route option sets the list view filter, how can I reset the filter from another project so it would display tasks only related to this project (currently the field is not available and the old filter is used)

Thank You