  We investigate a dynamical Coulomb blockade effect and its role in the
enhancement of current-current correlations in a three-terminal device with a
multilevel splitter, as well as with two quantum dots. Spectral decomposition
analysis shows that in the Y-terminal system with a two level ideal splitter,
charge fluctuations at a level with a lowest outgoing tunneling rate are
responsible for a super-Poissonian shot noise and positive cross-correlations.
Interestingly, for larger source-drain voltages, electrons are transferred as
independent particles, when three levels participate in transport, and double
occupancy is allowed. We can explain compensation of the current correlations
as the interplay between different bunching and antibunching processes by
performing a spectral decomposition of the correlation functions for partial
currents flowing through various levels. In the system with two quantum dots
acting as a splitter, a long range feedback effect of fluctuating potentials
leads to the dynamical Coulomb blockade and an enhancement of shot noise.
