It is an electrophilic aromatic substitutions reaction. Because the $\mathrm{COO}^{-}$acts as an electron withdrawiry group to one phenyl group ard a moderate electron donating group to the other pheryl group the nitration will occur on the phenyl group where $\mathrm{COO}^{-}$is acting as ars electron donating group.
The major product of the nitration will have the
$\mathrm{NO}_2$ in the para position because the or tho position is partially blocked by the large COPh grơup.