I have recently started using 4-player games on the SNES emulator. I can tell you that I had to install and use lr-snes to get it working right. When I would try to use lr-snes9x2010 the player 2 controller would simultaneously move players 2 - 4 at the same time.

As quicksilver said, the best way to handle it is to save overrides for the specific games. I also saved the alternate emulator as the default for those games only. I have successfully gotten 4P to work on Super Bomberman 1 and 2, NBA Jam and NBA Jam TE for the SNES.

@m0nkey12345 What RetroPie image are you using ?
Can you post the output of lsusb and cat /proc/bus/input/devices ?

@TheJullasicFox

If you had read it, you would in the first instance post the information requested in https://retropie.org.uk/forum/topic/3/read-this-first so that help can be offered. You will also notice that in this instructional thread it states "please create a new topic and add the following relevant information so that we can help narrow down the cause of your issue." You have not done this so help cannot be offered.

If you are thinking "why not?" at this stage then consider your request "I tried configuring it, but it won't even detect at all HELP!!!". It's a very strange question. What version of retropie? What Emulator? What did you "try" to do? What do you want help with? Your configs? Where are they?

Finally, you say you read it? In the instructional thread, it clearly states "Make sure your topic title summarises the issue - do not use topic titles like "HELP ME". A better title would be "USB Controller will not control Kodi after update" - if that is what you are actually having an issue with - it's not at all clear. What is Kodi's update? Can you use the controller in emulationstation? What version of Kodi are you referring to? etc. etc. etc.

This is so that others may search for your problem. So, did you read it? No. By now, help could have been offered but nobody knows what you did or what you tried. Hopefully, my explantion of how best to get fast help will assist you in future posts.