  Recent studies indicate that the progenitors of merging black hole (BH)
binaries from young star clusters can undergo a common envelope phase just like
isolated binaries. If the stars emerge from the common envelope as naked cores,
tidal interactions can efficiently synchronize their spins before they collapse
into BHs. Contrary to the isolated case, these binary BHs can also undergo
dynamical interactions with other BHs in the cluster before merging. The
interactions can tilt the binary orbital plane, leading to spin-orbit
misalignment. We estimate the spin properties of merging binary BHs undergoing
this scenario by combining up-to-date binary population synthesis and accurate
few-body simulations. We show that post-common envelope binary BHs are likely
to undergo only a single encounter, due to the high binary recoil velocity and
short coalescence times. Adopting conservative limits on the binary-single
encounter rates, we obtain a local BH merger rate density of ~6.6 yr^-1 Gpc^-3.
Assuming low (<0.2) natal BH spins, this scenario reproduces the trends in the
distributions of effective spin Xeff and precession parameters Xp inferred from
GWTC-2, including the peaks at (Xeff, Xp) ~ (0.1, 0.2) and the tail at negative
Xeff values.
