I store my levels in TileEd files, while have a name like “region_1.tmx”
In my application’s data, I have a list of names, one for each level.
The game logic selects the level (by number, in my case) and then gets the filename.
I end up with code the looks like this:
CCTMXTiledMap* _map = CCTMXTiledMap::create(this->getCurrentLevel()->filename());
There are different ways to do it, but my approach is to store each level, it’s behavior, objects and layout in a TMX file and then associate that file with a level ID. It also makes it easy to reuse levels.