  Beam neutrino oscillation experiments typically employ only one detector at a
certain baseline, apart from the near detector that measures the unoscillated
neutrino flux at the source. Lately, there have been discussions of having
detectors at two different baselines in one of the future long-baseline
neutrino oscillation experiments. We study the potential advantage of a general
dual-baseline system and perform analysis with a specific example of the
envisioned T2HKK experiment. We introduce a new parameter to exploit the
correlation between the oscillations at both baselines, and show how it can
help in determining the mass hierarchy and the CP phase in the neutrino sector.
Our study and findings can be generically used for any dual-baseline system.
