Navigate to Tools>Privacy>Organisational Structure.  If you have not used the Organisational Structure before, click the Start button on the left-hand Organisational Structure side panel, and a top-level folder will appear. 

• Enter the name of the top-level folder; typically, this is your organisation's name. 
• Click away from the folder, and the name will be recorded: 

• Right-click on the folder to add a group-level folder; typically, this is a division or department.  You can add up to 5 deep, group-level folders and can delete or rename the group-level folders by also right-clicking on the relevant folder.

To add a user to the Organisational Structure, search for the relevant user within the left-hand side user's panel, then click and drag the user to the required folder on the right-hand side Organisational Structure panel.  Ensure you drag and place the user onto the folder name (see example below): 

Remember: Save your progress before exiting the Organisational Structure page to ensure your work is saved.