Stellar-mass black hole mergers detected by LIGO and Virgo detector network point towards a population of objects with at least up to ~50 solar masses. The origin of these massive binaries is still unknown. In galactic centers, dynamical processes cause black holes to congregate, resulting in mergers. It is also possible that black holes formed in previous mergers encounter other black holes, resulting in so-called hierarchical mergers. Here, we analyze the parameters of LIGO/Virgo's published events to understand their astrophysical origin.