I have calendar and I have 5 different groups. I have an approval workflow. Now I want to have 5 different workflows for 5 groups but each workflow has to detect the group of the user and send the email to appropriate team leader. I have done sending email and approval workflow. But how can I detect the user group?
There isn't a way to check that natively that I know of from a workflow. There is a third party product that does.
Use the If this user is a member of this sharepoint group action from Useful Sharepoint Designer Custom Workflow Activities.
Another option would be using some custom script on the page where the user is submitting the item and use a web service call to fetch the groups(s) the user belongs to and populate a hidden column that you could then reference in the workflow.