Bound states in the continuum (BICs) can manifest as vortex polarization singularities in momentum space.The BICs at Γ point are proved to be protected by the rotational symmetry, and previous studies have explored the at-Γ BICs split into pairs of circularly polarized states with opposite chirality after breaking the in-plane inversion symmetry. As another type of conventional BICs, off-Γ BICs have been less explored in their evolution and modulation relations compared to their at-Γ counterparts. Here, we investigate the evolution of circularly polarized states spawning from off-Γ BICs by selectively breaking of in-plane and out-of-plane symmetry. The circularly polarized states exhibit distinct evolutionary trajectories under different symmetry-breaking conditions. This study offers an effective approach for manipulating the evolution of circularly polarized states in momentum space from off-Γ BICs, holding promise for potential applications in the field of polarization modulation and topological photonics.