  A search is presented for long-lived particles produced in pairs in
proton-proton collisions at the LHC operating at a center-of-mass energy of 13
TeV. The data were collected with the CMS detector during the period from 2015
through 2018, and correspond to a total integrated luminosity of 140 fb$^{-1}$.
This search targets pairs of long-lived particles with mean proper decay
lengths between 0.1 and 100 mm, each of which decays into at least two quarks
that hadronize to jets, resulting in a final state with two displaced vertices.
No significant excess of events with two displaced vertices is observed. In the
context of $R$-parity violating supersymmetry models, the pair production of
long-lived neutralinos, gluinos, and top squarks is excluded at 95% confidence
level for cross sections larger than 0.08 fb, masses between 800 and 3000 GeV,
and mean proper decay lengths between 1 and 25 mm.
