According to 7spot and Bulbanews, a new area is available to unlock with Pok√©mon Dream Radar by using a secret command. This area is known as Special Parts C. If you’d like to unlock this area, then you will be required to hit the following buttons: X, Y, L, R, Left, Right, Y, X.
With this command, you will also be able to obtain Hoothoot. The moves of this Hoothoot are Tackle, Hypnosis, Growl and Foresight.
Sources: Bulbanews, 7spot