You may schedule and post content to your Linkedin personal profiles and company pages.
Connecting a Linkedin Profile:
Once logged in, your Linkedin profile and company pages you have admin access to will show up from the list. Tick to select those you want to add and click Save and Continue.
Once you have connected your Linkedin account, it will now show in your list of Target Profiles when composing a message:
UPDATE: As of April 11, 2018, Linkedin has completely closed of groups to all partners and integrators. Read this article for more information.