diff --git a/modules/site_tools_group_helpers/site_tools_group_helpers.info.yml b/modules/site_tools_group_helpers/site_tools_group_helpers.info.yml
new file mode 100644
index 0000000..72309f1
--- /dev/null
+++ b/modules/site_tools_group_helpers/site_tools_group_helpers.info.yml
@@ -0,0 +1,8 @@
+name: 'Site Tools — Group Helpers'
+type: module
+description: 'Utilitários reutilizáveis para integração com o módulo Group.'
+core_version_requirement: ^10.3 || ^11
+package: Custom
+dependencies:
+  - site_tools:site_tools
+  - group:group
diff --git a/modules/site_tools_group_helpers/site_tools_group_helpers.install b/modules/site_tools_group_helpers/site_tools_group_helpers.install
new file mode 100644
index 0000000..28dfd46
--- /dev/null
+++ b/modules/site_tools_group_helpers/site_tools_group_helpers.install
@@ -0,0 +1,27 @@
+<?php
+
+/**
+ * @file
+ * Install hooks for site_tools_group_helpers.
+ */
+
+declare(strict_types=1);
+
+/**
+ * Implements hook_install().
+ *
+ * Applies the options_select widget to any entity_reference field already
+ * configured to use the site_tools_group_helpers selection handler, for
+ * example after a config import followed by module installation.
+ */
+function site_tools_group_helpers_install(): void {
+  $field_configs = \Drupal::entityTypeManager()
+    ->getStorage('field_config')
+    ->loadByProperties(['field_type' => 'entity_reference']);
+
+  foreach ($field_configs as $field_config) {
+    if ($field_config->getSetting('handler') === 'site_tools_group_helpers') {
+      _site_tools_group_helpers_set_widget($field_config, 'options_select', []);
+    }
+  }
+}
diff --git a/modules/site_tools_group_helpers/site_tools_group_helpers.module b/modules/site_tools_group_helpers/site_tools_group_helpers.module
new file mode 100644
index 0000000..666ca7e
--- /dev/null
+++ b/modules/site_tools_group_helpers/site_tools_group_helpers.module
@@ -0,0 +1,98 @@
+<?php
+
+/**
+ * @file
+ * Module hooks for site_tools_group_helpers.
+ */
+
+declare(strict_types=1);
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\field\FieldConfigInterface;
+
+/**
+ * Implements hook_form_FORM_ID_alter() for field_config_edit_form.
+ *
+ * Removes the #required constraint from the target_bundles checkboxes when
+ * the field references the 'group' entity type, allowing the selection to be
+ * left empty (= any group type) regardless of which handler is active.
+ */
+function site_tools_group_helpers_form_field_config_edit_form_alter(array &$form, FormStateInterface $form_state): void {
+  $field = $form_state->getFormObject()->getEntity();
+
+  if ($field->getFieldStorageDefinition()->getSetting('target_type') !== 'group') {
+    return;
+  }
+
+  $target_bundles = &$form['settings']['handler']['handler_settings']['target_bundles'] ?? NULL;
+  if ($target_bundles !== NULL) {
+    $target_bundles['#required'] = FALSE;
+  }
+}
+
+/**
+ * Implements hook_field_config_update().
+ *
+ * When a field switches to the site_tools_group_helpers selection handler,
+ * automatically updates all its form displays to use the options_select widget.
+ * When it switches away, reverts to entity_reference_autocomplete.
+ */
+function site_tools_group_helpers_field_config_update(FieldConfigInterface $field_config): void {
+  $handler = $field_config->getSetting('handler');
+  $original_handler = $field_config->original?->getSetting('handler');
+
+  if ($handler === $original_handler) {
+    return;
+  }
+
+  if ($handler === 'site_tools_group_helpers') {
+    _site_tools_group_helpers_set_widget($field_config, 'options_select', []);
+  }
+  elseif ($original_handler === 'site_tools_group_helpers') {
+    _site_tools_group_helpers_set_widget($field_config, 'entity_reference_autocomplete', [
+      'match_operator' => 'CONTAINS',
+      'match_limit' => 10,
+      'size' => 60,
+      'placeholder' => '',
+    ]);
+  }
+}
+
+/**
+ * Updates the widget type for a field across all its form displays.
+ *
+ * @param \Drupal\field\FieldConfigInterface $field_config
+ *   The field config entity.
+ * @param string $widget_type
+ *   The widget plugin ID to apply.
+ * @param array $settings
+ *   The widget settings to apply.
+ */
+function _site_tools_group_helpers_set_widget(FieldConfigInterface $field_config, string $widget_type, array $settings): void {
+  $entity_type_id = $field_config->getTargetEntityTypeId();
+  $bundle = $field_config->getTargetBundle();
+  $field_name = $field_config->getName();
+
+  $form_displays = \Drupal::entityTypeManager()
+    ->getStorage('entity_form_display')
+    ->loadByProperties([
+      'targetEntityType' => $entity_type_id,
+      'bundle' => $bundle,
+    ]);
+
+  foreach ($form_displays as $form_display) {
+    $component = $form_display->getComponent($field_name);
+    if ($component === NULL) {
+      continue;
+    }
+
+    $form_display->setComponent($field_name, [
+      'type' => $widget_type,
+      'weight' => $component['weight'],
+      'region' => $component['region'] ?? 'content',
+      'settings' => $settings,
+      'third_party_settings' => $component['third_party_settings'] ?? [],
+    ]);
+    $form_display->save();
+  }
+}
diff --git a/modules/site_tools_group_helpers/src/Plugin/EntityReferenceSelection/MemberGroupSelection.php b/modules/site_tools_group_helpers/src/Plugin/EntityReferenceSelection/MemberGroupSelection.php
new file mode 100644
index 0000000..30f5554
--- /dev/null
+++ b/modules/site_tools_group_helpers/src/Plugin/EntityReferenceSelection/MemberGroupSelection.php
@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\site_tools_group_helpers\Plugin\EntityReferenceSelection;
+
+use Drupal\Core\Entity\Attribute\EntityReferenceSelection;
+use Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\group\Entity\GroupMembership;
+
+/**
+ * Restricts group selection to groups where the current user is a member.
+ *
+ * Use this handler on any entity_reference field that targets the 'group'
+ * entity type when only the groups the current user belongs to should appear
+ * as options. Users with no memberships will see an empty list.
+ */
+#[EntityReferenceSelection(
+  id: 'site_tools_group_helpers',
+  label: new TranslatableMarkup('Member groups (current user)'),
+  entity_types: ['group'],
+  group: 'site_tools_group_helpers',
+  weight: 0,
+)]
+class MemberGroupSelection extends DefaultSelection {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+    $form = parent::buildConfigurationForm($form, $form_state);
+
+    // Allow leaving group types empty (= any type), matching the behaviour
+    // of the default selection handler.
+    if (isset($form['target_bundles'])) {
+      $form['target_bundles']['#required'] = FALSE;
+    }
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {
+    $query = parent::buildEntityQuery($match, $match_operator);
+
+    $memberships = GroupMembership::loadByUser($this->currentUser);
+
+    if (empty($memberships)) {
+      // User has no memberships — return an empty result set.
+      $query->condition('id', 0, '=');
+      return $query;
+    }
+
+    $gids = array_map(fn($m) => $m->getGroupId(), $memberships);
+    $query->condition('id', $gids, 'IN');
+
+    return $query;
+  }
+
+}