  The measurement of hard scatterings in proton-nucleus collisions has resulted
in a greater understanding of both the proton and nuclear structure. ATLAS
measured the centrality dependence of the dijet yield using 165 nb$^{-1}$ of
$p$+Pb data collected at $\sqrt{s_{_\text{NN}}}$ = 8.16 TeV in 2016. The event
centrality, which reflects the $p$+Pb impact parameter, is characterized by the
total transverse energy registered in the Pb-going side of the forward
calorimeter. The central-to-peripheral ratio of the scaled dijet yields,
$R_\mathrm{CP}$, is evaluated, and the results are presented as a function of
variables that reflect the kinematics of the initial hard parton scattering
process. The $R_\mathrm{CP}$ shows a scaling with the Bjorken-$x$ of the parton
originating from the proton, $x_p$, while no such trend is observed as a
function of $x_\mathrm{Pb}$. This analysis provides unique input to
understanding the role of small proton spatial configurations in $p$+Pb
collisions by covering parton momentum fractions from the valence region down
to $x_p \sim 10^{-3}$ and $x_\mathrm{Pb}\sim 4\cdot10^{-4}$.
