  LBQS 0302-0019 is a blue quasar (QSO) at z ~ 3.3, hosting powerful outflows,
and residing in a complex environment consisting of an obscured AGN candidate,
and multiple companions, all within 30 kpc in projection. We use JWST NIRSpec
IFS observations to characterise the ionized gas in this complex system. We
develop a procedure to correct for the spurious oscillations (or 'wiggles') in
NIRSpec single-spaxel spectra, due to the spatial under-sampling of the point
spread function. We perform a quasar-host decomposition with the QDeblend3D
tools, and use multi-component kinematic decomposition of the optical emission
line profiles to infer the physical properties of the emitting gas. The
quasar-host decomposition allows us to identify i) a low-velocity component
possibly tracing a warm rotating disk, with a dynamical mass Mdyn $\sim
10^{11}$ Msun and a rotation-to-random motion ratio $v_{rot}$/$\sigma_0 \sim
2$; ii) a spatially unresolved ionised outflow, with a velocity of $\sim$ 1000
km/s and an outflow mass rate of $\sim 10^4$ Msun/yr. We also detect eight
interacting companion objects close to LBQS 0302-0019. Optical line ratios
confirm the presence of a second, obscured AGN at $\sim 20$ kpc of the primary
QSO; the dual AGN dominates the ionization state of the gas in the entire
NIRSpec field-of-view. This work has unveiled with unprecedented detail the
complex environment of this dual AGN, which includes nine interacting
companions (five of which were previously unknown), all within 30 kpc of the
QSO. Our results support a scenario where mergers can trigger dual AGN, and can
be important drivers for rapid early SMBH growth.
