  We consider a collection of weakly interacting diffusion processes moving in
a two-scale locally periodic environment. We study the large deviations
principle of the empirical distribution of the particles' positions in the
combined limit as the number of particles grow to infinity and the time-scale
separation parameter goes to zero simultaneously. We make use of weak
convergence methods providing a convenient representation for the large
deviations rate function, which allow us to characterize the effective
controlled mean field dynamics. In addition, we obtain equivalent
representations for the large deviations rate function of the form of
Dawson-G\"artner which hold even in the case where the diffusion matrix depends
on the empirical measure and when the particles undergo averaging in addition
to the propagation of chaos.
