  We present that, if unitarizing the $B^{(*)}B^{(*)}$ scattering amplitudes in
the constituent interchange model, one can find two bound state poles for
$(I_{tot},S_{tot})=(0,1)$ $BB^*$ and $B^*B^*$ system, which corresponds to two
$I(J^P)=0(1^+)$ doubly bottomed molecular states. Furthermore, it is noticed
that the virtual states in $(1,0)$ $BB$, $(1,1)$ $BB^*$, $(1,0)$ $B^*B^*$, and
$(1,2)$ $B^*B^*$ systems could produce enhancements of the module squares of
the scattering $T$-matrix just above the related thresholds, which might
correspond to $I(J^P)=1(0^+)$, $1(1^+)$, and $1(2^+)$ doubly bottomed molecular
states, respectively. The calculation may be helpful for searching for the
doubly bottomed molecular state in future experiments.
