How do I create a mask?

Hey y'all!

I'm decently new to construct 3, I have only been working with it since around December of this year.

I'm working on a game right now, and I need to make a mask for it to work. The basic setup is this

I have 3 layers, the top layer is my light, I can turn it on and off with ctrl, all it does is show a white circle and it follows my mouse

layer 2, the middle layer, has a completely black screen, this is going yo show only when the light is off

layer 3, the bottom layer, is where everything will be taking place. I have a version of my scene that is a bit lit it,i want to create the illusion that the light is lighting up the scene, but making a mask that shows what it in my layer 3, through the light on layer 1, (the light is set to 25% opacity, but i want layer 3 to show up as 100% through that)

does anybody know how to do this? iv tried a bit but i have no clue, and i don't want the entire thing to change when i turn on the light, it just looks tacky

thanks!

Construct has some built in examples. Take a look at the Simple Lighting example in the Beginner Examples list.

Thank you so much! the example helped a lot!