This area displays full information on the selected node or arc.
  When you select a node or an arc in the graph, the corresponding
  information is highlighted in the lower pane.  This information
  includes the name, type, domain, and usage, the module that contains
  the item; and the file where the item resides.

  To expand information about an item, click MB1 on the icon in the
  left-hand column.  To go to source, doubleclick MB1 on an item name.