How to organize firbase db structure and edit in VUEJS?

Question

firebase

how to properly organize the structure of the project, the
code can be conditionally divided into two parts
a tree with nested parts
districts
microdistricts
streets
houses
this part will not change much
, but in houses, apartments will be added/deleted/edited
apartments should be added to the general tree or can a separate node be created? and how to make a link
this is the first question
and the second
I have a District component this is the root level
I get from the base districts

export  let rayons = FirebaseApp.database().ref('rayons')

in the component I use

name: "rayon",
        firebase: {
            rayons: rayons
        },

how to get to neighborhoods

firebase: {
            rayons: rayons.child(АЙДИ РАОНА).child(МИКРОРАЙОНЫ)
        },