Setting up a discovered attack: threat
Besides the forcing moves checks and captures, a third application is a threat. Examples of threats are attacking a piece, a checkmate threat or threatening to promote. The goal of the threat here is again to set up a discovered attack. After preparing a battery and finding a piece to target, a discovered attack or a discovered check follows with material gain.
What do you have to do?
Set up a discovered attack via a threat (attack a piece, generate a mate threat or threaten to promote). Afterwards, win material by performing the discovered attack or discovered check.