RuleTile with sibling layer tilemaps? z-axis siblings?

[64n35h4]

Hi

I'm not sure how to pharse the headline.. but I'm trying to use the module (RuleTile in specific) to create a tile for creating edge tiles (over water/lava etc..)

I got a grid with several layers I want to create 2 layers (assuming layer Ground and layer Edge) Layer Ground would be grass with patches of water (attached a picture) Layer Edge would be just the edge tiles on the border of the water patches As seen in the picture, some of the tiles work with rotation etc, because there's other this/not-this/sametype in the neightborhood (assuming they're on the same tilemap)

I was wondering how can I check for neightbors on the z-axis? tried to create a public tilemap property on the Rule and passing the relavent tilemap, but was ineffective. (The RED "X" are null in the Edge layer, but i'd like to "check" the type of the tile below/above/or on a layer by name?)

Would appriciate any direction. Thank you.