Contained in Brettspiel Adventskalender 2017 for day 6.

The mini expansion contains 8 new province tiles "Mango village" you can build by using two of a kind (color doesn't matter) and the normal building action.
They give small bonuses when being placed like river movement, karma, new dice, upgrade, money. In addition they contain new spots for your workers to score any two of your mango villages again (scaled like the markets for player number).
Finally there is a new brown yield tile for the Navaratnas variant which gives you 3$ for each mango village in your prov ...