  Recently, new observables in LHC inclusive events with three tagged jets were
proposed. Here, we extend that proposal to events with four tagged jets. The
events are characterised by one jet in the forward direction, one in the
backward direction with a large rapidity distance $Y$ from the first one and
two more jets tagged in more central regions of the detector. In our setup,
non-tagged associated mini-jet multiplicity is present and needs to be
accounted for by the inclusion of BFKL gluon Green functions. The projection of
the cross section on azimuthal-angle components opens up the opportunity for
defining new ratios of correlation functions of the azimuthal angle differences
among the tagged jets that can be used as probes of the BFKL dynamics.
