There are different ways to give back and you can invent yours. The idea is for a business to become a bit more socially driven and a bit less profit driven. Create less inequalities or even address them; involve the local community; invest in social or environmental projects; partner with charities or NGO; give employees profit sharing; give employees paid training time and/or paid volunteer time; choose suppliers that share the same social values.
To go further, you can explore the vision of a Social Business from Professor of Economics Muhammad Yunus here: http://www.muhammadyunus.org/index.php/social-business/social-business
There are also different social enterprise networks who give tips and promote social entrepreneurship like the Social Entreprise Alliance: https://socialenterprise.us/about/social-enterprise/