Navigating the relationship between the royal government and the general public required a dedicated mediator, a role fulfilled by Pethahiah son of Meshezabel. Commentators agree that he held a highly respected position as an appointed official who resided directly within the royal court. His status was so significant that he served as a close personal advisor to King Darius [רש״י].
His practical authority covered the civil needs of the population. This position was strictly focused on everyday, civic matters that fell completely outside the jurisdiction and management of the Temple [מלבי״ם].
Regarding his exact day-to-day duties, the primary approach among commentators is that he acted as a dedicated advocate for the people. In this capacity, he stood before the king to present the public's needs and request whatever support or resources they required [רש״י, מצודת דוד וביאור שטיינזלץ]. Conversely, another perspective suggests that his responsibilities were more administrative on behalf of the crown, focusing specifically on collecting taxes, tributes, and other royal dues owed by the population [רלב״ג].