Where is there an example of subjunctive mood in "Macbeth"?
Much of Macbeth relates to predictions and thoughts/wishes expressed by the witches and Macbeth. These are examples of subjunctive mood.
The witches predictions they make to Macbeth which startle him because they reflect what he is already thinking, Macbeth's plotting for example his identification of Banquo as someone who must be removed are examples of subjunctive mood. You need access to the text to give specific quotes.