The phrase "businesslike manner" means behaving in a professional, organized, and efficient way, just like how people typically conduct themselves in a business setting. Full definition
«Prima facie, one might have expected commercial men to frame their agreement in a more businesslike manner so as to cover the point, if this was what they intended.» (newlawjournal.co.uk)
c (1): characterized by or conforming to the technical or ethical standards of a profession (2): exhibiting a courteous, conscientious, and generally businesslike manner in the workplace (roypumphrey.com)
We help you work out the complications that can otherwise bog down your case in as amicable and businesslike a manner as possible. (orlandodivorcehelp.com)