High-resolution and accurate path delay estimation (PDE) is a prerequisite for channel impulse response (CIR)-based localization. Several superresolution path delay estimation (SPDE) algorithms are proposed to provide precise path delay estimates while utilizing limited bandwidth. Moreover, multi-band SPDE enables the combination of frequency resources on non-consecutive bands. However, such combination may result in a hidden ambiguity problem related to the matrix structure and the underlying channel. In this paper, we propose a flexible PDE matrix structure that clearly identify the ambiguity. Consequently, the ambiguous estimates can be mitigated, benefiting from this flexibility. In addition, we provide examples and performance evaluations showing the impact of ambiguity on the performance and the corresponding solution.