  We study a new physics scenario with two inert and one active scalar
doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2 \times Z'_2$
symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$
transformation and the other odd under the $Z'_2$ one. Such a construction
leads to a two-component Dark Matter (DM) model. It has been shown that, when
there is a sufficient mass difference between the two DM candidates, it is
possible to probe the light DM candidate in the nuclear recoil energy in direct
detection experiments and the heavy DM component in the photon flux in indirect
detection experiments. With the DM masses at the electroweak scale, we show
that, independently of astrophysical probes, this model feature can be tested
at the Large Hadron Collider via scalar cascade decays in $2 \ell +
\cancel{E}_T$ final states. We study several observable distributions whose
shapes hint at the presence of the two different DM candidates.
