So I thought I post this to help people out with the achievement, seeing how it wouldn't be that much fun to some people doing these challenges I want to save time for them lol.
This save is all challenges are done gold, but you can just do any challenge and gold it and you'll still get the achievement. You may even get a bronze and still get the Challenge Domination achievement.
Enjoy everyone and I'm glad I can give back to the community. :D
For co-op challenge achievement