Falling Snow behind a layer?

Hi!

This might have a really simple answer that i’m missing: I’ve created my falling snow but i want it to fall behind another layer (so it ‘peeps’ though).

I created my snow on a layer under the top layer and everything, but when i test the scene, the snow is on top…

Also - I want to make the ‘snow’ go upwards - i’ve tried changing minuses/plusses and the snow does go upwards, but the group of snow also moves upwards and gradually out of view?

Any suggestions would be greatly appreciated!

Jennie