Adopting a Relative Child

If you adopt a child then it can of course join you in Germany under the provisions of a family reunion visa. But Germany will need official documentation. I have no personal knowledge of the exact procedures  and am not sure if a child that is not without a parent can be adopted from abroad from Germany directly. Likely you will have to do the adoption in the Philippines under Filipino regulations. So your first step is probably contacting the proper authorities in the Philippines first.

Your first step should be contacting your local Jugendamt, which is in charge of adoptions.
But do not hold your hopes hight: Adoptions of kids from third world countries are almost impossible in Germany (to prevent child trafficking, which was rampant under adoption disguise in the past) and a local adoption elsewhere is almost certainly not recognised here (so don't follow Tom's advise above!).
German friends of mine adopted a baby in Singapore - through the official (and known as incorruptible) channels there - and cannot bring her to Germany, because she would not be their child here! (They knew this and are o.k. with it, though.)

I agree with most of Beppi's comments that adoptions from most third world countries are no longer happening due to abuses.

But the poster has a very different situation. It's not a German trying to get whatever foreign kid; it's a Filipino looking to take custody of a Filipino relative. One will have to get confirmation from both countries in the end but I would first look into how it would work from the Philippines. German officials are careful but not heartless or stupid. There can be many reasons a child is taken up by grandparents, aunts, uncles or siblings if there are compelling reasons.

The relationship can be a significant factor; not a case of one more or less selling a kid due to poverty or a profit motive. And while family reunion visas are usually limited to a spouse and minor children; other relatives are occasionally given exemption due to dire circumstances. So I doubt it would be easy but still worth inquiring about.

Tom is right!
I did not think of the possibility that you want to adopt a deceased near relative's child because he/she would otherwise have no guardian. In such cases, although the buerocratic hurdles will probably be high, it might be possible to get the local adoption in your home country recognised here on humanitarian grounds.
You should definitely talk to your local Jugendamt first!

@Baby Joi Hi Baby Joi, I am in the same situation like you - trying to adopt my niece and bring her to Germany. How did your process go? Can you share your experiences?

Thanks in advance!