The subiculum has been considered a critical brain region through which the hippocampal information is transmitted to various cortical areas, but little is known about its exact role in episodic memory. Hippocampal place cells tend to have single place fields, and change their firing rates depending on the information relevant to task, such as visual scene or behavioral choice. In contrast, subicular cells exhibit broad and spatially invariant firing fields, which makes direct comparison challenging. To address this issue, we adapted spiking-phase methods to parse multiple subfields from the single broad firing field of a subicular neuron. Single neuron activities and local field potentials were obtained while rats were performing a hippocampal-dependent memory task that required associative learning between scene stimuli and behavioral choices. By examining the spiking phases in relative to the theta rhythm, we successfully separated overlapping place fields within a neuron. This analysis revealed that subicular neurons encode a variety of task-related information together by their multiple subfields, which may support associative learning in a way that differed from the unitary representation seen in hippocampal place cells. This work provides a new perspective on the function of the subiculum in episodic memory, underscoring the importance of development of tailored analytical methods to understand brain function, especially when traditional methods fall short.