> I've already looked and there aren't an expression to get the tile's Y
Did you look in the manual?
When using tiles in the object's conditions, actions and expressions, positions are generally given in tiles instead of layout co-ordinates. You can convert between tile positions and layout co-ordinates using the PositionToTileX/Y and TileToPositionX/Y expressions.
Yes, and the expression is TilemapSolids.TileToPositionY(TileY), in my case.
But what about the "(TileY)"? This is exactly what I want to retrieve.