Identify the right tense: ‘My father –– before I came’.

ব্যাখ্যা

"Had left" is right. Two past actions are compared: the father's leaving happened first, and my coming happened later. The earlier one takes the past perfect (had + past participle), the later one stays in simple past ("came"). "Will leave" is future, and "would be leaving" or "had been leaving" do not show a finished earlier action.