diff --git a/src/Flexible.php b/src/Flexible.php
index f0927411..3ce4a010 100644
--- a/src/Flexible.php
+++ b/src/Flexible.php
@@ -207,7 +207,7 @@ public function resolve($resource, $attribute = null)
      * @param  string  $requestAttribute
      * @param  object  $model
      * @param  string  $attribute
-     * @return void
+     * @return null|Closure
      */
     protected function fillAttribute(NovaRequest $request, $requestAttribute, $model, $attribute)
     {
@@ -217,9 +217,17 @@ protected function fillAttribute(NovaRequest $request, $requestAttribute, $model
 
         $this->buildGroups($model, $attribute);
 
-        $this->syncAndFillGroups($request, $requestAttribute);
+        $callbacks = collect($this->syncAndFillGroups($request, $requestAttribute));
 
         $this->value = $this->resolver->set($model, $attribute, $this->groups);
+
+        if($callbacks->isEmpty()) {
+            return;
+        }
+
+        return function() use ($callbacks) {
+            $callbacks->each->__invoke();
+        };
     }
 
     /**
@@ -227,7 +235,7 @@ protected function fillAttribute(NovaRequest $request, $requestAttribute, $model
      *
      * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
      * @param  string  $requestAttribute
-     * @return void
+     * @return array
      */
     protected function syncAndFillGroups(NovaRequest $request, $requestAttribute)
     {
@@ -236,7 +244,9 @@ protected function syncAndFillGroups(NovaRequest $request, $requestAttribute)
             return;
         }
 
-        $this->groups = collect($raw)->map(function($item, $key) use ($request) {
+        $callbacks = [];
+
+        $this->groups = collect($raw)->map(function($item, $key) use ($request, &$callbacks) {
             $layout = $item['layout'];
             $key = $item['key'];
             $attributes = $item['attributes'];
@@ -245,10 +255,13 @@ protected function syncAndFillGroups(NovaRequest $request, $requestAttribute)
 
             if(!$group) return;
 
-            $group->fill(ScopedRequest::scopeFrom($request, $attributes, $key));
+            $scope = ScopedRequest::scopeFrom($request, $attributes, $key);
+            $callbacks = array_merge($callbacks, $group->fill($scope));
 
             return $group;
         });
+
+        return $callbacks;
     }
 
     /**
diff --git a/src/Http/ScopedRequest.php b/src/Http/ScopedRequest.php
index 40aa8d03..4149416c 100644
--- a/src/Http/ScopedRequest.php
+++ b/src/Http/ScopedRequest.php
@@ -62,7 +62,7 @@ protected function getScopeState($group, $attributes)
 
             // Sub-objects could contain files that need to be kept
             if($attribute->isAggregate()) {
-                $scope['files'] = array_merge($scope['files'], $this->getNestedFiles($value, $attribute->group));
+                $scope['files'] = array_merge($scope['files'], $this->pullNestedFiles($value, $attribute->group));
                 $scope['input'][$attribute->name] = $value;
                 continue;
             }
@@ -81,30 +81,37 @@ protected function getScopeState($group, $attributes)
     }
 
     /**
-     * Get nested file attributes
+     * Get & remove nested file attributes from given array
      *
      * @param  array  $iterable
      * @param  null|string  $group
      * @return array
      */
-    protected function getNestedFiles($iterable, $group = null)
+    protected function pullNestedFiles(&$iterable, $group = null)
     {
         $files = [];
         $key = $this->isFlexibleStructure($iterable) ? $iterable['key'] : $group;
 
-        foreach ($iterable as $attribute => $value) {
+        foreach ($iterable as $original => $value) {
             if(is_array($value)) {
-                $files = array_merge($files, $this->getNestedFiles($value, $key));
+                $files = array_merge($files, $this->pullNestedFiles($value, $key));
+                $iterable[$original] = $value ? $value : null;
                 continue;
             }
 
-            $attribute = FlexibleAttribute::make($attribute, $group);
+            $attribute = FlexibleAttribute::make($original, $group);
 
-            if(!$attribute->isFlexibleFile($value)) continue;
+            if(!$attribute->isFlexibleFile($value)) {
+                continue;
+            }
 
             $files[] = $attribute->getFlexibleFileAttribute($value);
+
+            $iterable[$original] = null;
         }
 
+        $iterable = array_filter($iterable);
+
         return $files;
     }
 
diff --git a/src/Layouts/Layout.php b/src/Layouts/Layout.php
index b188670c..06e0dbf2 100644
--- a/src/Layouts/Layout.php
+++ b/src/Layouts/Layout.php
@@ -230,13 +230,18 @@ public function getResolvedValue()
      * Fill attributes using underlaying fields and incoming request
      *
      * @param  \Laravel\Nova\Http\Requests\NovaRequest  $request
-     * @return void
+     * @return array
      */
     public function fill(ScopedRequest $request)
     {
-        $this->fields->each(function($field) use ($request) {
-            $field->fill($request, $this);
-        });
+        return  $this->fields->map(function($field) use ($request) {
+                    return $field->fill($request, $this);
+                })
+                ->filter(function($callback) {
+                    return is_callable($callback);
+                })
+                ->values()
+                ->all();
     }
 
     /**