...
You can drag and drop any item into the Organization Chart panel to link them with the existing items. For example, you can drag and drop a position into an organization unit and a user into a position.
...
Organization Unit
Organizational Units give a hierarchical structure, and when properly designed can ease administration. You can only create one root organization unit that representing your company and parenting all the departments below. Clicking one of the organization units will bring up an edit tools menu as shown below. You can use this menu to add new child units below, add positions to it, edit its properties, set it disabled or delete it.
...