How to discover Variable from multiple actors on screen?

@Supremative I know this is probably extremely easy but I’m scratching my brain on remembering how to do this part I circled in red. In an earlier image you referenced a “KEYS” and “Local Key” variable. This one only says “Key”, is this a new variable? I’m unsure hot to connect it in a way that shows “Target----Key”

Thank you for your help!