Hi,
I am not certain what exactly you would like to get so maybe say a bit more if you would like more specific help. If the extra layer modifies the states in the first but is not optically active it should come out like that.
We do not have a tag option for optical properties but we have recently made the optical transition matrix elements into a LowLevelEntity (so it is accessible to users directly).
You might be able to take the elements and do the manipulations you need.
There are functions calculateMomentumMatrixElements and calculateDipoleTransitionMatrixElements that can be imported like this
from NL.Calculators.LowLevelEntities import calculateDipoleTransitionMatrixElements
The function takes: p= calculateDipoleTransitionMatrixElements(configuration, kpoint, number_of_states)
where p is a 3 x number_of_states x number_of_states matrix (includes states up to the specified number).