Each panel section in the user manager can be collapsed, or expanded. By default they are all expanded...although you may not see anything in a section unless you are overriding the default setting.

When a section is collapsed, it will have a dark grey color to it. Clicking the '+' sign will expand it. In my example screenshot, the 'Tunnels' section is expanded. The setting in the 'Tunnels' panel is currently being inherited from the 'vnc' user.