Rational allocation of system operating reserve cost is a crucial mechanism for the electricity market to incentivize market participants to proactively reduce uncertainties. Accurately tracing the impact of market participants on the operating reserve requirement is a prerequisite. The impact on the requirement is closely related to the quantification pattern of the operating reserve requirement. The industrial practices mainly set the operating reserve requirement as the maximum value between the contingency reserve and the net load reserve, which exhibits discrete characteristics. However, existing reserve cost allocation methods do not consider the above characteristic, leading to an unreasonable cost allocation pattern. As a result, the resource allocation efficiency of the electricity market is limited. Furthermore, existing research mainly focuses on the intra-provincial operating reserve. The cost allocation considering the supply and demand of intra- and inter-provincial operating reserve is not explored. To address the above issue, considering the total intra- and inter-provincial reserve costs, this paper proposes a requirement traceability oriented hierarchical allocation method for operating reserve costs. Firstly, a common requirement sharing pattern is proposed to decompose intra- and inter-provincial reserve costs into contingency reserve costs and net load reserve costs, considering the discrete characteristic of the requirement quantification pattern based on the maximum value in industrial practices. Subsequently, considering the superposition characteristic of uncertainties from different categories of market participants, the contingency reserve costs are further allocated based on common requirement sharing, and the net load reserve costs are further allocated based on modified substitution benefit. Case studies based on practical data validate the rationality of the proposed method.