Based on several different dynamic-mechanical and rheological experiments we discuss some common features of structural filler reorganization in filled elastomers and in polymer nanocomposites of hybrid materials consisting of a thermoplastic melt (LDPE) and nanofillers (Mg/Al based Layered Double Hydroxide). In the elastomer case the discussion is possible when studying the kinetics of the modulus recovery with experimental set-ups where the stiffness response on repeated amplitude steps can be measured; or when monitoring the structural relaxation phenomena during heat treatment (annealing) of the uncross-linked as well as cross-linked composites. In the case of filled thermoplastic melts the structural evolution of filler clusters is studied with non-linear shear flow experiments. We discuss a simple kinetic model of autonomous (but forced by restrictions) saturation in an aggregated growth process which reflects the role of complexity and cooperative aggregation within the considered system.