Hi,
Easy Profile does not do this natively but it is possible by creating a simple Plugin, you can follow these steps:
- Download our skeleton plugin (you can find it at http://docs.easy-profile.com/index.php/article/triggers)
- Install it from Joomla Installer
- Enable it from Extensions->Plugins
- Open file /plugins/jsn/skeleton/skeleton.php
- Remove sample functions: "triggerFieldAvatarUpdate" and "triggerProfileUpdate"
- Add a function like this:

public function triggerProfileUpdate($user,&$data,$changed,$isNew)

{

    if(isset($data['HERE_THE_ALIAS_OF_YOUR_FIELD']) && !empty($data['HERE_THE_ALIAS_OF_YOUR_FIELD'])){

        $value = $data['HERE_THE_ALIAS_OF_YOUR_FIELD'];

        if($value == 'opt1') {

            /* HERE THE CODE TO ADD USER TO K2 GROUP, FOR EXAMPLE WITH A SQL QUERY */

        }

        else{

            /* HERE THE CODE TO REMOVE USER FROM K2 GROUP, FOR EXAMPLE WITH A SQL QUERY */

        }

    }

}

IMPORTANT NOTE: This code is not tested and not supported, this is only for example purpose.

Thanks for the answer, but it was a little vague, after configuring the code, what is the procedure to create a select with this function? I didn't see any way to customize the selects, is there any specific field to use this skeleton?

Hi,
before use this code you have to create the field, for example a field of type select with alias like "k2_group" and following options

normal|Normal

author|Author

each option need to have following syntax "value|text"

So after create the field you can customize the code with something like

public function triggerProfileUpdate($user,&$data,$changed,$isNew)

{

    if(isset($data['k2_group']) && !empty($data['k2_group'])){

        $value = $data['k2_group'];

        if($value == 'author') {

            /* HERE THE CODE TO ADD USER TO K2 GROUP, FOR EXAMPLE WITH A SQL QUERY */

        }

        else{

            /* HERE THE CODE TO REMOVE USER FROM K2 GROUP, FOR EXAMPLE WITH A SQL QUERY */

        }

    }

}