In orbifold gauge theory and gauge-Higgs unification models, gauge anomaly flows with an Aharonov-Bohm phase $\theta_H$ in the fifth dimension.
We analyze $SU(2)$ gauge theory with doublet fermions in the flat $M^4 \times (S^1/Z_2)$ spacetime
and in the Randall-Sundrum (RS) warped space.
With orbifold boundary conditions the $U(1)$ part of gauge symmetry remains unbroken
at $\theta_H = 0$ and $\pi$.
Chiral anomalies smoothly vary with $\theta_H$ in the RS space.
Anomaly coefficients associated with this anomaly flow are expressed
in terms of the values of the wave functions of gauge fields at the UV and IR branes in the RS space
and parity conditions of fermion fields.
Holography in anomaly flow is observed.
Conditions for the anomaly cancellation turn out independent of $\theta_H$.