The Pierre Auger Observatory has been collecting data for over $19$ years, reaching more than $135\,000\,$km$^2\,$yr$\,$sr of accumulated exposure, with the surface detectors spread over $3000\,$km$^2$.
A remarkable discovery is the large-scale dipole structure with a total amplitude of $7.4\%$ for energies above $8\,$EeV.
The observed modulation in right ascension has a statistical significance of $6.8\sigma$.
The dipolar pattern in the events with energies between $8$ and $16\,$EeV has a statistical significance of over $5\sigma$.
The Pierre Auger Collaboration has also reported an increase in the dipole amplitude with energy.
This anisotropy is understood to be of extragalactic origin, as the maximum of the dipolar component is located $\sim115^\circ$ away from the Galactic Center.
In the same energy range, the observed evolution of the depth of maximum shower development with energy indicates a progression towards heavier composition of cosmic rays with increasing energy.
This contribution presents a novel approach to a search for composition-enhanced large-scale anisotropy.
On the one hand, lighter events have higher rigidity than their heavier counterparts with similar energy; therefore, their trajectories are less affected by magnetic fields.
The expected effect is a higher anisotropy in the arrival direction of a subset of events with smaller mass and charge than the anisotropy in the overall flux of cosmic rays.
On the other hand, the attenuation length is distinct for each mass group, leading to different horizon of cosmic ray sources for each of them.
Under a source-agnostic model, we investigate the dipole amplitude as a function of rigidity.
Using a simulation library, we analyze the possibility of measuring a separation in total dipole amplitude between two sub-populations distinct in mass of the Auger Phase I dataset.