In this sentence, the interplay of the part in bold and the rest of the sentence is in question.
1 I learned that NOUN + に + VERB can have the meaning of doing VERBAL COMPLEX as a symbolic action in relation to NOUN, like here: "田中さんが結婚祝いにこのお皿をくださいました。" => Tanaka gave us this plate as present for our wedding.
In this case 世界中の人 would fill the place of NOUN, then comes に, and then である fills the place of VERB.
2 The use of ように makes things a bit difficult for me. So far, One of the various ways of using ように seems the most probable to me: Verb 1 + ように + Verb 2 => Verb 1 is a means to reach Verb 2, like this: 泳げるように毎日練習しています。 "I practice every day so that I can swim"
3 So the whole sentence would read like this: "Concerning Map B, it was made so that there is equality for all people in the world."
Another problem I have is that the "symbolic action" character of 平等である isn't as clear as I think it should be. Especially if I translate "...so that there is...", the indicative makes it more than symbolic in my opinion. On the other hand, even in the phrase in 1, which was taken from my textbook, I do have issues with the description "symbolic action". Symbolic actions usually don't have a tangible manifestation, I think. At least not as tangible as a present I can touch and use etc.. But well, maybe I'm just too picky. It's hard enough to describe language and it's still a minor issue after all.