Defines the next view to give focus to when the next focus is Android.Views.FocusSearchDirection.Left. If the reference refers to a view that does not exist or is part of a hierarchy that is invisible, a Java.Lang.RuntimeException will result when the reference is accessed.

Must be a reference to another resource, in the form "@[+][package:]type:name" or to a theme attribute in the form "?[package:][type:]name".

[Android Documentation]