On the group invite friends page, it's using input/friendpicker to filter and choose friends to invite, which is a nice feature. I want to keep this feature, but at the same time add a same invite friends form using input/userpicker. 

// elgg/mod/groups/views/default/resources/groups/invite.php
$content = elgg_view_form('groups/invite', array(
    'id' => 'invite_to_group',
    'class' => 'elgg-form-alt mtm',
), array(
    'entity' => $group,
));

I can see invite friends is using groups/invite action, my question is that can I use this action for my custom userpicker form or I still need to register a custom action like groups/invite_userpicker? Thanks