Catching up with these, check out the Microsoft Dynamics GP 2015 Feature of the Day: Vendor Approval Workflow
Microsoft Dynamics GP 2015 Feature of the Day: Vendor Approval Workflow – Microsoft Dynamics GP Community
Payables & ReceivablesInstall, Upgrade & AdminTips & Hidden FeaturesGP 2015
Archived post from 2014. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.