Complex sentence: It is one of several advocacy and public relations groups created by Richard Berman, whose Washington, D.C.-based public affairs firm, Berman and Company, specializes in research, communications and advertising.
Split into simpler sentences: It is one of several advocacy and public relations groups created by Richard Berman. Berman's Washington, D.C.-based public affairs firm, Berman and Company, specializes in research, communications and advertising.