Simple as that
HashMap1.get("aKey") -- > return hashMap2
.get("anotherKey") --> return hashMap3
.get("yetAnotherKey") --> return hashMap4
.get("MyString"); --> return String
There is something wrong with the adding part.
Now you have structure like below.
hashmap1 --> hashmap2 --> String
String myString = hashMap1.get("aKey").get("MyString");
That is how it should be.