Federal Advisory Committee Transparency Act This bill revises provisions regarding federal advisory committees, including to (1) require designation of committee members as special government employees or representatives, (2) apply the Federal Advisory Committee Act (FACA) to subcommittees and subgroups, and (3) require publication of certain information about advisory committees. The bill requires appointments to advisory committees to be made without regard to political affiliation or campaign activity, unless required by federal statute. Each agency, prior to appointing members to an advisory committee, must solicit nominations for potential committee members. The agency shall solicit nominations at least once every two years. The bill provides statutory authority for the designation of advisory committee members as special government employees (if they are appointed to exercise their individual best judgement) or representatives (if they are appointed to represent a nongovernment entity). Agencies may not designate committee members as representatives to avoid federal ethics rules. Each agency shall make available on its website specified information about each of the agency's advisory committees, including membership, meeting minutes, and notices of future meetings. The General Services Administration must also publish this information. The bill revises requirements for Advisory Committee Management Officers, including to require them to be senior officials with expertise in implementing FACA. The Government Accountability Office shall report on agency compliance with FACA.