Wondering about the difference between these two types of organizational models when it comes to parents, siblings, etc.
@Ana, for Hierachical tree and Nested doll navigation is explained in detail here at (interaction-design.org) https://goo.gl/QKkVJK (along with Hub and Spoke Navigation, Bento Box Navigation, Filtered View Navigation)
Navigation is a vital part of the user experience for mobile apps and getting it right will ensure that users can open your app, get to where they want to be and then get moving on something else. This in turn, is likely to incentivize long-term adoption of your mobile app rather than short-term use and then abandonment. Navigation need careful attention to get it just right for your users.
Hierarchical Tree Navigation
This is the most common form of navigation in traditional websites and applications. It provides a top-level category for navigation followed by further layers of content in sub-categories below that level.
The drawback is that this model can quickly become difficult to accommodate on the mobile screen; the more content you have, the more difficult it is to squash all that data into the screen.
The image below shows how an app might handle the navigation through the different sects of Islam using a hierarchical structure.
Nested Doll Navigation
This is a more typical navigation system for mobile apps. Each time the user moves to a level in the hierarchy of navigation – new items below it are revealed. It uses a move from broad overviews to more specific details. It works well on the small screen but it can be challenging to support horizontal movement between sections when implemented. It gets its name from the concept of nested dolls which are a series of dolls which fit within each other.