How beneficial is study Group & Discussions prevail in obtaining a job? How does it create a Job Opportunity

Well, confidence about your knowledge and fluency are what mainly tested in the job interviews.Whether you study by self or in groups main things one need to cultivate are confidence, improving communication skills,gain knowledge about the topics which are necessary for appearing in interviews.
Studying in groups motivates you to work more and more,team building,one can gain knowledge in your weak areas from the other group members,coming accross various and different approaches for a single problem.
In the job interviews they mainly test your presence of  mind while solving a problem /issue , how well you can cope up with other employees and mingle with them, how well you behave as a leader for several other people around you, how well things resolve in your presence  and how confident you are, how honest you are.
Many of the skills are innate, but communication skills, team work, gaining knowledge can be easily learnt from group studies or discussions.