My Spaces / Limit to groups of current user - Checkbox does not work as expected

I did not find any existing issue for this even if this functionality seems to be broken for a while now. I think priority is major because it makes the user dashboard a little senseless. Looks like this is broken since oa_core_og_group_ref_views_handler_filter_entityreference_autocomplete uses the select2widget functionality. Anyway the shown results are not complete.

Steps to reproduce in 2.43:

1. Create Space - create Discussion Section - Create Discussion Post
2. Create Subspace - create Discussion Section - Create Discussion Post
3. Add a "View: Open Atrium Comment Topic List: Topics" - Pane and check "Limit to groups of current user"

The first problem was easy to find. In oa_core.module you have the following code:

    // If "My Spaces" is checked, restrict to user's groups
    global $user;
    if (!empty($exposed[$id . '_mine'])) {
      $groups = oa_core_get_groups_by_user($user, 'node');
      if ($groups && ($gids = array_intersect_key($groups, $filter->get_value_options()))) {
        $exposed[$id] = $gids;
        $filter->options['expose']['multiple'] = TRUE;
      }
      else {
        // If restricting to My Spaces but the user has no spaces, fail the build
        return FALSE;
      }
    }

The result of array_intersect_key() is wrong because oa_core_get_groups_by_user() returns an array with indexes and we would need the ids as keys. This could be easily done by replacing

if ($groups && ($gids = array_intersect_key($groups, $filter->get_value_options()))) { with
if ($groups && ($gids = array_intersect_key(array_combine($groups, $groups), $filter->get_value_options()))) {

After this it took me some while to dig into it and I don't really know how to handle it correctly. This is why it makes no sense if I provide a patch. I think the problem is located in oa_core_og_group_ref_views_handler_filter_entityreference_autocomplete.inc. In exposed_validate(&$form, &$form_state) it seems like $form_state['values']['og_group_ref_target_id'] is used for filtering which is not set correctly. I was able to find the correct values in $form['og_group_ref_target_id ']['og_group_ref_target_id ']['#value'].

Hope this helps!
Greetings,
Leo