Firebase includes different options for implementing a hierarchical database, but Thorium implements the Root Level Collection data structure as described in this document: https://firebase.google.com/docs/firestore/manage-data/structure-data
In order to understand how tou can create a hierarchical database with Thorium & Firebase, you can download our template app that implements a 3 levels hierarchical database (Continents-Countries-Cities)
Download Template
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