Dionysus was a god in Greek mythology, and his festivals were incredibly important in ancient Greek culture. The most famous festival in his honor was the City Dionysia (also known as the Great Dionysia) held in Athens.
During the City Dionysia, dramatic competitions were held, and playwrights like Aeschylus, Sophocles, Euripides, and Aristophanes competed to have their plays performed.
So, while there wasn't a single play titled "City Dionysus," it was the festival where many famous Greek plays were first performed.