"D", "4", "3", "2" Positions First Gear

WARNING: This page is about a different car, the 2013 Nissan Armada. However, it is still accessible from the selected car via links, so may be relevant.

The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
The 1st one-way clutch regulates reverse rotation of the rear sun gear.
The 3rd one-way clutch regulates reverse rotation of the front sun gear.
During deceleration, the mid sun gear turns forward, so the forward one-way clutch idles and the engine brake is not activated.

Fig 1: Power Transmission Diagram (D, 4, 3, 2 Positions First Gear)
Courtesy of NISSAN NORTH AMERICA, INC.