  The repeating fast radio burst FRB20190520B is an anomaly of the FRB
population thanks to its high dispersion measure (DM$=1205\,$pc/cc) despite its
low redshift of $z_\mathrm{frb}=0.241$. This excess has been attributed to a
large host contribution of $DM_{host}\approx 900\,$pc/cc, far larger than any
other known FRB. In this paper, we describe spectroscopic observations of the
FRB20190520B field obtained as part of the FLIMFLAM survey, which yielded 701
galaxy redshifts in the field. We find multiple foreground galaxy groups and
clusters, for which we then estimated halo masses by comparing their richness
with numerical simulations. We discover two separate $M_{halo}
>10^{14}\,M_\odot$ galaxy clusters, at $z=0.1867$ and $z=0.2170$, respectively,
that are directly intersected by the FRB sightline within their characteristic
halo radius \rvir{}. Subtracting off their estimated DM contributions as well
that of the diffuse intergalactic medium, we estimate a host contribution of
$DM_{host}=430^{+140}_{-220}\,$pc/cc or $DM_{host}=280^{+140}_{-170}\,$pc/cc
(observed frame) depending on whether we assume the halo gas extends to
$r_{200}$ or $2\times r_{200}$. This significantly smaller $DM_{host}$ -- no
longer the largest known value -- is now consistent with H$\alpha$ emission
measures of the host galaxy without invoking unusually high gas temperatures.
Combined with the observed FRB scattering timescale, we estimate the turbulent
fluctuation and geometric amplification factor of the scattering layer to be
$\tilde{F} G\approx4.5 - 11\,(\mathrm{pc^2\;km})^{-1/3}$, suggesting most of
the gas is close to the FRB host. This result illustrates the importance of
incorporating foreground data for FRB analyses, both for understanding the
nature of FRBs and to realize their potential as a cosmological probe.
