Repeater::make('members')
    ->schema([
        // your repeater fields
    ])
    ->extraItemActions([
        Action::make('addNewItem')
            ->icon('heroicon-m-plus')
            ->action(function (array $arguments, Repeater $component): void {
                $newUuid = Str::uuid()->toString();
                $items = $component->getState();
                $newItems = [];

                foreach ($items as $key => $value) {
                    $newItems[$key] = $value;
                    
                    if ($key === $arguments['item']) {
                            $newItems[$newUuid] = [];
                    }
                }

                $component->state($newItems);
                $component->getChildComponentContainer($newUuid)->fill();
                $component->callAfterStateUpdated();
            }),
    ])
    ->addable(false);

Repeater::make('members')
    ->schema([
        // your repeater fields
    ])
    ->extraItemActions([
        Action::make('addNewItem')
            ->icon('heroicon-m-plus')
            ->action(function (array $arguments, Repeater $component): void {
                $newUuid = Str::uuid()->toString();
                $items = $component->getState();
                $newItems = [];

                foreach ($items as $key => $value) {
                    $newItems[$key] = $value;
                    
                    if ($key === $arguments['item']) {
                            $newItems[$newUuid] = [];
                    }
                }

                $component->state($newItems);
                $component->getChildComponentContainer($newUuid)->fill();
                $component->callAfterStateUpdated();
            }),
    ])
    ->addable(false);