We report spectroscopic ellipsometry measurements of the anisotropy of the interband transitions parallel and perpendicular to the planes of $({\mathrm{LaTiO}}_{3})n({\mathrm{LaAlO}}_{3})5$ multilayers with $n=1--3$. These provide direct information about the electronic structure of the two-dimensional (2D) $3{d}^{1}$ state of the Ti ions. In combination with local density approximation, including a Hubbard $U$ calculation, we suggest that 2D confinement in the ${\mathrm{TiO}}_{2}$ slabs lifts the degeneracy of the ${t}_{2g}$ states leaving only the planar ${d}_{xy}$ orbitals occupied. We outline that these multilayers can serve as a model system for the study of the ${t}_{2g}$ 2D Hubbard model.