I get the feeling the C++ code shown below, which comes from the wpilib sample robot project, is close. The comments from the sample do state it's for the Java SmartDashboard but they don't explain how to set the chooser options for the LabView dashboard?
Code:
chooser = new SendableChooser();
chooser->AddDefault(autoNameDefault, (void*)&autoNameDefault);
chooser->AddObject(autoNameCustom, (void*)&autoNameCustom);
SmartDashboard::PutData("Auto Modes", chooser);