@dennis Thanks for asking, answers were really helpful to me.
I have the same Juyao Dual Arcade Joystick and I faced the same issue that you had.

My dual controller was recognized as one controller so I wasn't able to configure them separately.

My solution was this:

cd /opt/retropie/configs/all/retroarch-joypads cp Xin-Mo Xin-Mo Dual Arcade.cfg D_R_M JUYAO Dual Arcade.cfg

then edited D_R_M JUYAO Dual Arcade.cfg
replacing vendor and product_id

the final file should look similar to this:

input_device = "D_R_M JUYAO Dual Arcade" input_driver = "udev" input_vendor_id = "0314" input_product_id = "0328" input_up_axis = "-1" input_down_axis = "+1" input_left_axis = "-0" input_right_axis = "+0" input_select_btn = "7" input_start_btn = "12" input_a_btn = "0" input_b_btn = "3" input_x_btn = "5" input_y_btn = "2" input_l_btn = "1" input_r_btn = "4" input_l2_btn = "9" input_r2_btn = "8" input_l_x_plus_axis = "+0" input_l_x_minus_axis = "-0" input_l_y_plus_axis = "+1" input_l_y_minus_axis = "-1"

After doing that, I was able to configure them separately on retroarch.

@gautchh Attach and config a keyboard in ES, go into the emulator of your choice and enter the rgui menu. There you can navigate to Settings, Input and configure your controller. Make sure the right controller-device is selected and try bind all.

If your controllername does not show up increase the number of players (or devices) under Input and try again.

Another way to get your controller working properly is using xboxdrv, which emulates an xbox controller and makes mapping it in games easier.