The presence of mutual-coupled interference in full-duplex self-backhauling heterogeneous networks raises challenges and difficulties in practical scenarios. In this letter, we address this issue by developing a two-tier non-orthogonal multiple access (NOMA) scheme together with efficient power control to enable aggressive frequency reuse and alleviate co-channel interference. For the considered multi-tier and multi-cell NOMA scenario, we formulate a power minimization problem, and develop an efficient algorithm with guaranteed convergence to enable optimal power control, such that users' data demand is satisfied and backhauling bottleneck is avoided. Numerical results show the fast convergence of the proposed algorithm, and demonstrate that NOMA is in particular favorable for the high-demand cases in power savings.