Click "Data" from Menu and then select "WBS", then click the "Structure" button. the numbers from 1 to 10 represent levels of WBS. Which means the structure of WBS can have levels ranging from 1 to 10. Enter the symbol in separator field that you want to use for separating different levels of the WBS. Example of work breakdown structure of a GIS Project in Primavera Project Planner P3.