public function formatAssociatableResource(NovaRequest $request, $resource)
    {
        $relation = explode(".", $this->groupedBy);

        $groupedBy = count($relation) == 2
                   ? $resource->{$relation[0]}->{$relation[1]}
                   : $resource->{$this->groupedBy};

        return array_filter([
            'groupedBy' => $groupedBy,
            'avatar' => $resource->resolveAvatarUrl($request),
            'display' => $this->formatDisplayValue($resource),
            'value' => $resource->getKey(),
        ]);
    }