  We investigate the scalar sector in an extension of the Minimal
Supersymmetric Standard Model (MSSM) containing a $SU(2)$ Higgs triplet of zero
hypercharge and a gauge singlet beside the $SU(2)$ scalar doublets. In
particular, we focus on a scenario of this model which allows a light
pseudoscalar and/or a scalar below $100$ GeV, consistent with the most recent
data from the LHC and the earlier data from the LEP experiments. We analyze the
exotic decay of the discovered Higgs $(h_{125})$ into two light (hidden) Higgs
bosons present in the extension. The latter are allowed by the uncertainties in
the Higgs decay $h_{125}\to WW^*$, $h_{125}\to ZZ^*$ and $h_{125}\to
\gamma\gamma$. The study of the parameter space for such additional
scalars/pseudoscalars decay of the Higgs is performed in the gluon fusion
channel. The extra hidden Higgs bosons of the enlarged scalar sector, if they
exist, will then decay into lighter fermion paris, i.e., $b\bar{b}$,
$\tau\bar{\tau}$ and $\mu\bar{\mu}$ via the mixing with the doublets. A
detailed simulation using PYTHIA of the $2b+2\tau$, $\geq 3\tau$, $2b+2\mu$ and
$2\tau+2\mu$ final states is presented. From our analysis we conclude that,
depending on the selected benchmark points, such decay modes can be explored
with an integrated luminosity of 25 fb$^{-1}$ at the LHC at a center of mass
energy of 13 TeV.
