The file reference locator option is useful when you need to move a file reference in the scene view via its group node. The locator also acts as a visual cue for the reference whenever the reference is unloaded. The locator option is only available in the Reference Options window when the Group option is selected. The locator option groups the contents of the referenced file under a locator, annotated with the reference node name. You can load or unload a reference within the scene by right-clicking on the locator and selecting from the context sensitive menu.
For more information, see File > Create Reference.