Layers, levels (5)
I believe the answer is:
tiers
I believe this is a double definition.
'layers' is the first definition.
(I know this)
'levels' is the second definition.
('tier' can be a synonym of 'level')
(Other definitions for tiers that I've seen before include "Layers, levels" , "Layers, strata" , "Tries (anag.)" , "aprons for kids" , "Layers or thicknesses" .)