Eye for an Eye
Lykos wants to kill Heracles' sons. This is a metaphor for the fact that he believes no son will grow up and forgive the man who killed their father. Lykos believes them to be a threat every day they have breath in their lungs.
Chorus
The Chorus shouts at the audience to stop Lykos, as he is a foreigner who has taken command of their city. This is a metaphor for their belief that only a man from Thebes can rule their people, a foreigner will destroy the city.
Not to Exile
Megara won't allow her sons to be sent away in exile. The sentence of exile is a metaphor for living a life of poverty, which is far worse of a sentence than death.
Appeal to Lykos
Amphitryon appeals to Lykos in an attempt to stop him from executing him and his family. His appeal is a metaphor that no man can appeal to a fool and expect a reasonable outcome. Only a wise man can hear an appeal and respond with decency, a fool cannot. Lykos, apparently, is a fool.
Hades
Heracles is away in Hades performing his final labour as his family is prolonging their lives being cut short by Lykos. This is a metaphor for a city's at its weakest when their bravest men are away fighting great battles in distant lands, as those greedy for power seek to usurp it while their is the least resistance.