Manual Navigation turns off the Auto Scroll features of the controller window and allows you to select which tracks will display on an individual basis.
The default behavior of the Controller window is to automatically display the selected object animated tracks, and to hide them when the object is not selected in the viewport. Turning on Manual Navigation changes this behavior so that deselecting the object will not make the curves disappear from view.
When Manual Navigation is engaged, buttons appear in the Controller window next to the tracks, that allow you to expand or collapse individual containers such as objects or materials.
To collapse individual components in the Controller window:
An small minus sign within a circle appears to the left of the entry.
The tracks collapse. A plus sign within a circle appears.
When Manual Navigation is turned off, tracks expand based on Auto-Expand choices made on the Settings Auto Expand menu.