Some limitations of the user group functionality are presented below:
Changes to a user group (after it was added in the survey) will not cause changes to the survey permissions. For example, if new users are added to a user group that has been already granted survey permissions, the respective new users won't have the same survey permissions as the rest of the user group members. For this to happen, the updated user group has to be granted survey permissions again so that the new user group members can receive the same permissions as the rest of the user group members.
If you delete a user from a user group with survey permissions, the respective user will not lose the user group survey permissions. To remove his or her permission rights, delete the account from the survey permissions table.
Because the user group functions are still experimental, we kindly ask you to pay attention to any inconsistencies you may find while using LimeSurvey and report them via the bug tracker or the ticket system.
Some examples are provided below to help you better understand how a LimeSurvey user group works:
Informing members of a user group that they have received certain survey permissions
Granting certain permissions to a user group
Adding a user to a user group
As mentioned above, adding a user group behaves like a macro function that simply adds all the current members of the user group, easing the process of granting survey permissions. However, if a new member is added to that user group, that member will not automatically receive the rights that were previously granted to the other members of the user group. Therefore, you will have to repeat the steps shown in the example from above in order to grant him or her the same rights or you just add him or her separately, using the Add user function (from the 'Survey permission' panel).
Removing permissions of a user no longer in a user group
Removing them from the group should leave him without any user group permissions. However, this is not happening due to the limitations of the user group functionalities! If you delete the user from the user group, he or she still remains with the user group survey permissions. Therefore, a workaround is to manually delete the account from the 'Survey permissions' table.
Removing all user group members with access to a survey
As mentioned above, deleting a user from a group won't retrieve his survey permissions. The same goes for 'user groups'. Deleting a user group won't retrieve the survey permissions that were previously granted to the members of the respective user group. At the moment, the only viable solution is to have them manually removed from the 'Survey permissions' table.