  In this study, computational analysis of neutral Higgs bosons $h$, $H$ and
$A$ is carried out within the parameter space of Two Higgs Doublet Model (2HDM)
type-I in exact alignment limit of $\sin{(\beta - \alpha)} = 1$ at compact
linear collider. Assuming Compact Linear Collider (CLIC) scenario where the
electron-positron beams will be collided at $\sqrt{s}$ = 1.5 TeV. Two different
values of predicted integrated luminosities are used in our calculations, 1000
$fb^{-1}$ and 2500 $fb^{-1}$. Three signal processes $e^+ e^- \rightarrow Zhh
\rightarrow jjb\bar{b}b\bar{b}$, $e^+ e^- \rightarrow ZHH \rightarrow
jjb\bar{b}b\bar{b}$ and $e^+ e^- \rightarrow Zhh \rightarrow
jjb\bar{b}b\bar{b}$ are selected for analysis. The polarized colliding beams
are used to enhance the signal production cross-section. Low $\tan{\beta}$ and
equal Higgs masses regime is chosen in favor of Hadronic decay of $Z$ boson and
$H \rightarrow b\bar{b}$. Different signal scenarios are selected and event
generation is performed for each process separately. The $W$ and $Z$ boson, as
well as top quark backgrounds are analyzed. Signal significance is computed at
each Higgs mass hypothesis for three signal processes. After a comprehensive
study, we did not find sizeable amount of signal events on top of the
background but still, signal significance is found to be larger than 1, without
taking into account the detector effects and systematics. The maximum
calculated value of signal significance is observed to lie in the range of 150
$\leq$ $m_H$ $\leq$ 250 GeV for $Zhh$ while for $ZHH$ the range is 175 $\leq$
$m_H$ $\leq$ 200 GeV at 1000 $fb^{-1}$ and 175 $\leq$ $m_H$ $\leq$ 225 GeV
region at 2500 $fb^{-1}$. Similarly, for $ZAA$ process, the significance is
highest at $m_A$ = 175 GeV for both 1000 and 2500 $fb^{-1}$.
