  In this work, we investigate the form factors of the transitions $B_{(s)} \to
D_{0}^{\ast}(2300),D_{s0}^{\ast}(2317),$ $ D_{s1}(2460) $ and $ D_{s1}(2536)$
in the covariant light-front quark model (CLFQM), where these final states are
considered as P-wave excited charmed mesons. In order to obtain the form
factors for the physical transition processes, we need to extend these form
factors from the space-like region to the time-like region. The
$q^{2}$-dependence for each transition form factor is also plotted. Then,
combined with those form factors, the branching ratios of the two-body
nonleptonic decays $B_{(s)}\to D^*_{(s)0}(2300,2317)M, D_{s1}(2460,2536)M$ with
$M$ being a light pseudoscalar (vector) meson or a charmed meson are calculated
by considering the QCD radiative corrections to the hadronic matrix elements
with the QCD factorization approach. Most of our predictions are comparable to
the results given by other theoretical approaches and the present available
data.
