While an Environment Query can generate a number of Items based on getting an Actor type, it doesn't do that for Contexts. So, we need a way to have the Player's Pawn as a Context, which is where the EnvQueryContext_BlueprintBase comes into play.
Double click the PlayerContext Blueprint in the Content Browser to open it for editing.
Override the ProvideActorsSet Function:
The Override button is hidden until you mouse over the Functions portion of the My Blueprint panel.
This will override the default behavior of the function with the Blueprint Graph that opens:
Add a Get All Actors Of Class and connect it between the Provide Actor Set Node and the ReturnNode like this:
Finally set the Actor Class of the Get All Actors Of Class Node to Top Down Character, Compile, and Save.