The "Shut 'Em Down" collaboration you are likely looking for is a popular fan-made rather than an official studio single released by all four artists together.
: The most notable official song with this title is "Shut 'Em Down" by Onyx featuring DMX , released in 1998 on Onyx's album of the same name. Snoop Dogg, Dr. Dre, Ice Cube & DMX - Shut 'Em Down
While there is no official album release featuring Snoop Dogg , Dr. Dre, Ice Cube, and DMX on a song titled "Shut 'Em Down," the term is famously associated with several individual projects: The "Shut 'Em Down" collaboration you are likely
: There are numerous fan-made remixes on YouTube and SoundCloud that combine verses from these West Coast and East Coast legends over "Shut 'Em Down" or "Ruff Ryders" type beats. Snoop Dogg, Dr. Dre, Ice Cube & DMX - Shut 'Em Down