Have you already purchased the dimmers? If so, which option did you get? "/W/X3"? That seems to be the only variant that can do both analog and PWM dimming. You feed 0-4.5V into the analog dimmer wire to set the maximum brightness and hook the PWM wire to a a PWM output on the Arduino to fade from off to whatever brightness is set by the analog input.
The data sheet seems to be saying that the analog input adjusts the current output. That probably means that the light output will not change linearly with the analog dimmer input.
Perhaps you should get the '/W/X2" mode with PWM-Only. Then use an analog input on the Arduino to modify the PWM output to provide a "dimmer knob" effect.
What is it you wanted to accomplish with having both analog and PWM dimming?