I was an English major as an undergrad.

It sounds like you’re asking a question you’ve received for homework. While I don’t know exactly how your teacher or professor would want you to answer it, I am familiar with the play Antigone and can answer your questions from my perspective.

Wider community was a term created by your textbook or teacher or professor. As such, you’re probably not going to be able to find an exact definition of it online or in a dictionary. I think in terms of the play Antigone, it means the city of Thebes.

Antigone and Creon clashed over the rules of the king, Creon, versus the rules of religious practice in Thebes at that time. Creon believed he could rewrite the rules of Thebes anyway he wanted because he was, after all, the king. He believed being king had certain privileges no one could or would question. It made him feel powerful.

Antigone had no respect for any rules that clashed with the religious practice of dressing a body (in this case Polyneices’ body) for burial. She didn’t care that Creon didn’t like it. She was going to do it anyway. She also didn’t care that Creon was the king and she was only a woman and a commoner. She was going to do what was right with the gods.

This clash between Antigone and Creon affected the story in that it showed the people of Thebes (including Creon) that trying to prohibit anyone from doing what the gods demanded instead of what people demanded is a very bad idea. It will get the person who’s doing the demanding (and those following the person’s demand) in a lot of trouble.

From Wikipedia.com

-quote
All of Greece will despise him, and the sacrificial offerings of Thebes will not be accepted by the gods. The Chorus, terrified, asks Creon to take their advice. He assents, and they tell him that he should free Antigone and bury Polyneices. Creon, shaken, agrees to do it.
-endquote

Antigone and Creon are fighting over a couple of issues. Creon wants his authority unquestioned. He is a new leader and he wants to make sure everyone knows that he is the boss. He makes a fatal mistake when he orders everyone to disregard the rules of the gods. His problem is that he does not see that he is ordering his subjects to violate a higher power. This affects the larger community, in that if HE can order others to violate the rules the gods have decreed, what about the other rules?
Antigone wants to express her devotion to her brother and follow her religious beliefs. She is willing to openly defy the rules so that she can follow her religious convictions. The state, in the form of Creon, refuses. This affects the wider community because the state has an inherent interest in requiring rules be followed. Can we all follow the rules established by the state, but also express our religion properly?