diff --git a/app/Form/Actions/ParticipantIndexAction.php b/app/Form/Actions/ParticipantIndexAction.php
index 3157405e..df779bdc 100644
--- a/app/Form/Actions/ParticipantIndexAction.php
+++ b/app/Form/Actions/ParticipantIndexAction.php
@@ -6,6 +6,7 @@ use App\Form\Models\Form;
 use App\Form\Models\Participant;
 use App\Form\Resources\ParticipantResource;
 use App\Form\Scopes\ParticipantFilterScope;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
 use Illuminate\Pagination\LengthAwarePaginator;
 use Lorisleiva\Actions\Concerns\AsAction;
@@ -14,18 +15,32 @@ class ParticipantIndexAction
 {
     use AsAction;
 
+    /**
+     * @return HasMany<Participant>
+     */
+    protected function getQuery(Form $form, ParticipantFilterScope $filter): HasMany
+    {
+        return $form->participants()->withFilter($filter)->withCount('children')->with('form');
+    }
+
     /**
      * @return LengthAwarePaginator<Participant>
      */
     public function handle(Form $form, ParticipantFilterScope $filter): LengthAwarePaginator
     {
-        return $form->participants()->withFilter($filter)->with('form')->paginate(15);
+        return $this->getQuery($form, $filter)->paginate(15);
     }
 
-    public function asController(Form $form): AnonymousResourceCollection
+    public function asController(Form $form, ?int $parent = null): AnonymousResourceCollection
     {
         $filter = ParticipantFilterScope::fromRequest(request()->input('filter'));
-        return ParticipantResource::collection($this->handle($form, $filter))
-            ->additional(['meta' => ParticipantResource::meta($form)]);
+
+        $data = match ($parent) {
+            null => $this->handle($form, $filter),
+            -1 => $this->getQuery($form, $filter)->where('parent_id', null)->get(),
+            default => $this->getQuery($form, $filter)->where('parent_id', $parent)->get(),
+        };
+
+        return ParticipantResource::collection($data)->additional(['meta' => ParticipantResource::meta($form)]);
     }
 }
diff --git a/app/Form/Resources/ParticipantResource.php b/app/Form/Resources/ParticipantResource.php
index c8ad10a2..b200242f 100644
--- a/app/Form/Resources/ParticipantResource.php
+++ b/app/Form/Resources/ParticipantResource.php
@@ -25,6 +25,7 @@ class ParticipantResource extends JsonResource
             ...$this->getModel()->getFields()->present(),
             'created_at' => $this->created_at->format('Y-m-d H:i:s'),
             'created_at_display' => $this->created_at->format('d.m.Y'),
+            'children_count' => $this->children_count,
             'links' => [
                 'destroy' => route('participant.destroy', ['participant' => $this->getModel()]),
             ]
diff --git a/app/Form/Scopes/ParticipantFilterScope.php b/app/Form/Scopes/ParticipantFilterScope.php
index 1b117764..38ab982e 100644
--- a/app/Form/Scopes/ParticipantFilterScope.php
+++ b/app/Form/Scopes/ParticipantFilterScope.php
@@ -22,7 +22,6 @@ class ParticipantFilterScope extends Filter
      * @param array<string, mixed> $data
      */
     public function __construct(
-        public ?int $parent = null,
         public array $data = [],
     ) {
     }
@@ -45,14 +44,6 @@ class ParticipantFilterScope extends Filter
      */
     public function apply(Builder $query): Builder
     {
-        if ($this->parent === -1) {
-            $query = $query->whereNull('parent_id');
-        }
-
-        if (!is_null($this->parent) && $this->parent > 0) {
-            $query = $query->where('parent_id', $this->parent);
-        }
-
         foreach ($this->data as $key => $value) {
             if ($value === static::$nan) {
                 continue;
diff --git a/database/factories/Form/Models/ParticipantFactory.php b/database/factories/Form/Models/ParticipantFactory.php
index a155d6e3..7e265003 100644
--- a/database/factories/Form/Models/ParticipantFactory.php
+++ b/database/factories/Form/Models/ParticipantFactory.php
@@ -27,6 +27,7 @@ class ParticipantFactory extends Factory
     {
         return [
             'data' => [],
+            'parent_id' => null,
         ];
     }
 
diff --git a/routes/web.php b/routes/web.php
index 7c8b5352..69bcb924 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -163,7 +163,7 @@ Route::group(['middleware' => 'auth:web'], function (): void {
     Route::delete('/formtemplate/{formtemplate}', FormtemplateDestroyAction::class)->name('formtemplate.destroy');
     Route::post('/form', FormStoreAction::class)->name('form.store');
     Route::patch('/form/{form}/meta', FormUpdateMetaAction::class)->name('form.update-meta');
-    Route::get('/form/{form}/participants', ParticipantIndexAction::class)->name('form.participant.index');
+    Route::get('/form/{form}/participants/{parent?}', ParticipantIndexAction::class)->name('form.participant.index');
     Route::post('/form/{form}/is-dirty', IsDirtyAction::class)->name('form.is-dirty');
     Route::delete('/participant/{participant}', ParticipantDestroyAction::class)->name('participant.destroy');
 });
diff --git a/tests/Feature/Form/ParticipantIndexActionTest.php b/tests/Feature/Form/ParticipantIndexActionTest.php
index bdeac437..2a4a5559 100644
--- a/tests/Feature/Form/ParticipantIndexActionTest.php
+++ b/tests/Feature/Form/ParticipantIndexActionTest.php
@@ -2,7 +2,6 @@
 
 namespace Tests\Feature\Form;
 
-use App\Form\Fields\CheckboxField;
 use App\Form\Fields\TextField;
 use App\Form\Models\Form;
 use App\Form\Models\Participant;
@@ -127,30 +126,6 @@ class ParticipantIndexActionTest extends FormTestCase
             ->assertJsonCount(4, 'data');
     }
 
-    public function testItShowsOnlyRootMembers(): void
-    {
-        $this->login()->loginNami()->withoutExceptionHandling();
-        $form = Form::factory()->create();
-        Participant::factory()->for($form)->count(2)
-            ->has(Participant::factory()->count(3)->for($form), 'children')
-            ->create();
-
-        $this->callFilter('form.participant.index', ['parent' => -1], ['form' => $form])->assertJsonCount(2, 'data');
-        $this->callFilter('form.participant.index', ['parent' => null], ['form' => $form])->assertJsonCount(8, 'data');
-    }
-
-    public function testItShowsChildrenOfParent(): void
-    {
-        $this->login()->loginNami()->withoutExceptionHandling();
-        $form = Form::factory()->create();
-        $parents = Participant::factory()->for($form)->count(2)
-            ->has(Participant::factory()->count(3)->for($form), 'children')
-            ->create();
-
-        $this->callFilter('form.participant.index', ['parent' => $parents->get(0)->id], ['form' => $form])->assertJsonCount(3, 'data');
-        $this->callFilter('form.participant.index', ['parent' => $parents->get(1)->id], ['form' => $form])->assertJsonCount(3, 'data');
-    }
-
     public function testItPresentsNamiField(): void
     {
         $this->login()->loginNami()->withoutExceptionHandling();
@@ -191,4 +166,34 @@ class ParticipantIndexActionTest extends FormTestCase
             ->assertJsonPath('meta.columns.1.id', 'created_at')
             ->assertJsonPath('meta.columns.1.display_attribute', 'created_at_display');
     }
+
+    public function testItShowsOnlyParentParticipantsWhenFilterEnabled(): void
+    {
+        $this->login()->loginNami()->withoutExceptionHandling();
+        $form = Form::factory()->create();
+        $participant = Participant::factory()
+            ->has(Participant::factory()->for($form)->count(2), 'children')
+            ->for($form)
+            ->create();
+
+        $this->callFilter('form.participant.index', [], ['form' => $form])->assertJsonCount(3, 'data');
+        $this->callFilter('form.participant.index', [], ['form' => $form, 'parent' => -1])->assertJsonCount(1, 'data');
+        $this->callFilter('form.participant.index', [], ['form' => $form, 'parent' => $participant->id])->assertJsonCount(2, 'data');
+    }
+
+    public function testItShowsChildrenCount(): void
+    {
+        $this->login()->loginNami()->withoutExceptionHandling();
+        $form = Form::factory()->create();
+        $participant = Participant::factory()
+            ->has(Participant::factory()->for($form)->count(2), 'children')
+            ->for($form)
+            ->create();
+        Participant::factory()->for($form)->create();
+
+        $this->callFilter('form.participant.index', [], ['form' => $form, 'parent' => -1])
+            ->assertJsonPath('data.0.children_count', 2)
+            ->assertJsonPath('data.1.children_count', 0);
+        $this->callFilter('form.participant.index', [], ['form' => $form, 'parent' => $participant->id])->assertJsonPath('data.0.children_count', 0);
+    }
 }