Select backlog navigation levels for your team in Visual Studio Team Service

 

1. From your team’s backlog page, click the  (gear icon) to open the common configuration team settings.
   
2. Click the Backlogs tab and check the boxes of those backlog levels you want your team to manage.

   

3. To see the changes, open or refresh your team’s backlog web page.

Reff: https://www.visualstudio.com/en-us/docs/work/customize/select-backlog-navigation-levels