  Star cluster complexes such as the Carina Nebula can have formed in turbulent
giant molecular clouds. We perform a series of $N$-body simulations starting
from subclustering initial conditions based on hydrodynamic simulations of
turbulent molecular clouds. These simulations finally result in the formation
of star cluster complexes consisting of several subclusters (clumps). We obtain
the inter-clump velocity distribution, the size of the region, and the mass of
the most massive cluster in our simulated complex and compare the results with
observed ones (the Carina Nebula and NGC 2264). The one-dimensional inter-clump
velocity dispersion obtained from our simulations is $2.9\pm0.3$ and
$1.4\pm0.4$ km s$^{-1}$ for the Carina- and NGC 2264-like models, respectively,
which are consistent with those obtained from Gaia Data Release 2: 2.35 and
0.99 km s$^{-1}$ for the Carina Nebula and NGC 2264, respectively. We estimate
that the masses of the parental molecular clouds for the Carina Nebula and the
NGC 2264 are $4\times 10^5$ and $4\times 10^4M_{\odot}$, respectively.
