According to the ServiceNow documentation1, the planning console can show as many WBS levels as desired, starting from the level 1 to the lowest system components. The WBS levels can be expanded or collapsed by clicking the plus or minus icons next to the task names. The planning console also allows users to create, edit, and delete tasks, as well as add dependencies, assign resources, and track progress.
1:
https://docs.servicenow.com/bundle/vancouver-it-business-management/page/product/project-management/conc