Problem with advanced output and layers linked to each slice

[lucaaav]

Hi everyone!!
I'm kinda new to arena, but I'm starting to get used to it. The problem is that a colleague of mine set up the project file when I wasn't around and I can't go back to normal settings.
I'm working with three triangular screens, so he set them up in advanced output assigning to each screen a layer (eg. Layer 1 - Central panel, Layer 2 - Left triangle, Layer 3 - Right triangle, Layer 4 - full display).
I tried to set the input source of every slice to composition, so that every layer can send clips to the full display, however when I do so nothing shows up in the output and the screen is totally black.
How can I reverse what he did, so that for example on the central screen I can send clips from both Layer 1 and 4 ?
If I wasn't enough clear or you need further explanations or details let me know!!

Thanks to everyone that will answer me!

[tijnisfijn]

could you maybe add some screenshots/recording of your in and output settings in the advance screen settings. that would help a lot to figure out whats going on.

greetings