To connect 2-phase lights to a 3-phase circuit, start by creating a circuit that has 3 poles. Use the Circuiting command.
Ribbon: DM Electrical->Circuiting and Homeruns-> Circuiting
Pulldown Menu: DM Electrical->Circuiting and Homeruns->Circuiting
Select the circuit and press the Change # of Poles button on the right side of the dialog box. Set the Number of Poles to Three and press the OK button.
Press the Circuit to Phase button to circuit the light fixtures to specific phases of the circuit. You will be prompted for the phase to use for the first light fixture.
After you circuit one fixture, you can press ENTER once, then type S to change the phase to which you are connecting devices.