Top: example of the associated yield per-trigger particle $Y$ in TPC--FMD1,2 correlations as a function of $\Delta \eta^\prime$ and $\Delta \varphi^\prime$ for $\vert \eta \vert 0.8$ with $3 \pT^{\rm trig} 5$~GeV/$c$, $1 \pT^{\rm assoc} \pT^{\rm trig}$~GeV/$c$, $-0.9 \Delta\eta -0.7$ and $3.7 \Delta\varphi 4.2$ in high-multiplicity (left) and low-multiplicity (right) \pPb collisions at $\snn = 5.02$~TeV. Bottom: associated per-trigger yield after the subtraction of the scaled correlation distribution in low-multiplicity collisions(left)and fit of the distribution projected onto $\Delta\varphi^\prime$ with Eq.~(\ref{eq:3pc}).