  In this work, the branching ratio $\mathcal{B}[B\to K\chi_{c0}(2P)]$ is
extracted for the first time through the fit fractions in the newly measured
$B\to KD\bar{D}$ process by LHCb. With the rescattering mechanism, this
extracted branching ratio is reproduced well. Our study further enforces the
role of the newly measured $B\to KD\bar{D}$ process to establish the
$\chi_{c0}(2P)$ charmonium state, which is a crucial step when constructing
charmonium family.
