Accessing Parent App from Child


I want to be able to access parent app shell (a side bar and top nav for my website) from the child app (the main page). I have filters that are clicked in the sidenav that I need to be able to track the state of from my child component in my router-view so that I can update data. I am very new to Aurelia so I don’t know if this is the best practice or if I’m completely approaching the problem wrong.