Dynamical relaxation provides an interesting solution to the hierarchy problem, which allows to produce a large hierarchy of scales without abandoning the naturalness principle. The observed value of the electroweak scale is then a consequence of an interaction between the Higgs boson and a new axion-like field, a relaxion. Attempts at extending this mechanism to a two-doublet scenario (arXiv:1612.09128) show that without an additional symmetries of the potential the second doublet does not affect the relaxation process and generally remains vevless. However, non-trivial contributions are possible when some classes of accidental (possibly weakly-broken) symmetries are considered. This talk will present an attept at introducing the relaxation in the maximally-symmetric 2HDM (MS-2HDM), where the doublets are connected by an approximate SO(5) symmetry.