Studies of the transverse-spin dependent azimuthal asymmetries in the Drell-Yan process
permit to access the spin-dependent structure of the nucleon and especially to test the limited universality of its transverse-momentum dependent parton distributions.
In 2015 and 2018 the COMPASS Collaboration at CERN performed measurements of the $\pi^-$p $\rightarrow \mu^{+}\mu^{-}$X reaction at 190 GeV/$c$ pion beam and transversely polarised NH$_3$ target. This study covers the measurement of transverse spin asymmetries in Drell-Yan processes, and in particular, introduces a novel approach, in contrast to the conventional one, where the asymmetries were weighted by powers of a transverse momentum of the dimuon system with respect to the beam. This method facilitates the extraction of the transverse-momentum dependent parton distribution functions and opens an easy access to their certain $k_{\rm T}^2$ moments. Results of these analyses will be presented.