  We study the Ruderman-Kittel-Kasuya-Yosida interaction between magnetic
impurities embedded in $p$-doped transition metal dichalcogenide triangular
flakes. The role of underlying symmetries is exposed by analyzing the
interaction as a function of impurity separation along zigzag and armchair
trajectories, in specific parts of the sample. The large spin-orbit coupling in
these materials produces strongly anisotropic interactions, including a
Dzyaloshinskii-Moriya component that can be sizable and tunable. We consider
impurities hybridized to different orbitals of the host transition-metal and
identify specific characteristics for onsite and hollow site adsorption. In the
onsite case, the different components of the interaction have similar
magnitude, while for the hollow site, the Ising component dominates. We also
study the dependence of the interaction with the level of hole doping, which
supplies a further degree of tunability. Our results could provide ways of
controlling helical long range spin order in magnetic impurity arrays embedded
in these materials.
