Beginner question on Layer. Filer sequence

[5354photos]

I used GImp 3.0. So, there are Non Destructive Filters. I also use GMIC and layers. Somehow, I am confused the sequence of effects. My guess is
a/ The upper layer will take priority over the layer below
b/ Filters within the same layer also follow the same logic in a (Top is over bottom)

How should I use GMIC filters, eg I want to apply tone Enhance and then Freaky Details? In Input/Output, when to choose In Place/New Layer?

[denzjos]

It's best to always keep the original layer. So, if you're using G'Mic-Qt filters, choose "Save as New Layer."