  It is very likely that similar to the case of visible matter, dark matter too
is composed of more than one stable component. In this work we investigate a
two-component dark matter with one component from the visible sector and the
other from the hidden sector. Specifically we consider a $U(1)_X$ hidden sector
extension of MSSM/SUGRA where we allow for kinetic and Stueckelberg mass mixing
between the two abelian $U(1)'s$, i.e., $U(1)_X$ and $U(1)_Y$. We further
assume that the hidden sector has chiral matter which leads to a Dirac fermion
as a candidate for dark matter. The lightest neutralino in the visible sector
and the Dirac fermion in the hidden sector then constitute the two components
of dark matter. We investigate in particular MSSM/SUGRA models with radiative
breaking occurring on the hyperbolic branch where the Higgs mixing parameter
$\mu$ is small (order the electroweak scale) which leads to a lightest
neutralino being dominantly a higgsino. While dark matter constituted only of
higgsinos is significantly constrained by data on dark matter relic density and
by limits on spin independent proton-DM scattering cross section, consistency
with data can be achieved if only a fraction of the dark matter relic density
is constituted of higgsinos with the rest coming from the hidden sector. An
aspect of the proposed model is the prediction of a relatively light CP odd
Higgs $A$ (as well as a CP even $H$ and a charged Higgs $H^{\pm}$) which is
observable at HL-LHC and HE-LHC. We perform a detailed collider analysis search
for the CP odd Higgs using boosted decision trees in $\tau_h\tau_h$ final
states and compare the discovery potential at HL-LHC and HE-LHC. We show that
while several of the points among our benchmarks may be observable at HL-LHC,
all of them are visible at HE-LHC with much lower integrated luminosities thus
reducing significantly the run time for discovery.
