FinCEN Oversight and Accountability Act of 2023 This bill requires the Department of the Treasury to keep specified congressional committees informed of the activity of the Financial Crimes Enforcement Network (FinCEN), particularly regarding unlawful activity and any resulting corrective action. Further, Treasury must disclose to Congress and to the public (with some exclusions) all controlling documents delegating authority to or providing direction to FinCEN. Such disclosure includes any controlling documents in force upon enactment, any controlling documents issued thereafter, and any changes to controlling documents. The bill also limits the authority of Treasury to make certain exceptions regarding proposed or final rules related to FinCEN to the person performing the duties of the Secretary. The bill extends the time period during which Treasury must testify before Congress regarding FinCEN’s anti-money laundering programs for another five years. FinCEN must also hold an annual small business working group to provide guidance on beneficial ownership reporting obligations.