National firm Nelson Mullins Riley & Scarborough LLP has opened a Chicago office with four partners — Justin A. Barker, Dawn M. Beery, Scott A. McMillin and Matthew E. Nirider — who joined from Benesch. The attorneys will focus on litigation, including commercial litigation, product liability, securities and trade secret and bankruptcy matters.Barker practices in complex commercial litigation, product liability and toxic tort matters.Beery works on commercial litigation, product liability, securities …