Business coaching could refer to a manager who uses an approach or set of skills to promote growth within their business by motivating employees to do better with their job and be more effective, through positive encouragement, guidance, support; the manager takes on the roles of a business coach as a management style to help them effectively manage their sales, marketing and to work better with their team, or with other teams.
A business coach could also be somebody who is hired contractually to assess an area of weakness in a business that is preventing a business from progressing further, and growth has became stagnant; their job is to help small to medium size businesses manage their employees better, and coach managers on ways they can train their employees to do better with sales, marketing and work more effectively as a team, or for teams to work better with other teams.