Creating the User Group and assigning the roles for the user group

1.Creating the UserGroup:

We can get the userId and companyId from themeDisplay.    

UserGroup userGrp = UserGroupLocalServiceUtil.addUserGroup(userId, companyId, "Test User Group", "Test User Group Desc");

2.Assiging the user to UserGroup:

Here we can assign group of users but as of now we are assigning the only one user.

UserLocalServiceUtil.addUserGroupUsers(userGrp.getUserGroupId(), new long []{userId});

3.Assiging the roles to the usergroups:

          

Here we are getting the groupId of the UserGroup and also the role

long groupId =userGrp.getGroup().getGroupId()
Role roleId = RoleLocalServiceUtil.getRole(companyId, "Power User");
RoleLocalServiceUtil.addGroupRole(groupId, roleId);