Transnational White Supremacist Extremism Review Act This bill directs the Office of Intelligence and Analysis of the Department of Homeland Security (DHS) to develop and disseminate a threat assessment and reference aid regarding threats to the United States associated with foreign violent white supremacist extremist organizations. The threat assessment and reference aid (1) shall be developed in coordination with DHS's Office of Civil Rights and Civil Liberties and other appropriate agencies and may be informed by existing products developed by such office and agencies; and (2) shall include an overview of symbols, flags, or other references utilized by adherents of foreign violent white supremacist extremist organizations. The office shall share the threat assessment and reference aid with (1) state, local, and tribal law enforcement officials; and (2) owners and operators of online platforms to assist in identifying content that may be associated with a foreign violent white supremacist extremist organization that may violate the terms of service of such platforms, upon request from such platforms. Such office shall ensure that the threat assessment and reference aid does not contain the name or other identifiable information of any individual or organization engaged in lawful political or public discourse in the United States protected under the Constitution.