Dropdown list selecting a filter

I'm trying to get every properties of a json object in order to create a dropdown list.

I'm going to explain myself, for example :

I've got 2 json objects :

{"name":"Paul","age":"18","sport":"Basket","color":"Green"}
{"name":"Jhon","age":"20","sport":"Basket","fruit":"banana", "number":"5"}

I've got a dropdown list within {name,age,sport,color,fruit,number}. If I select name, I've got a second dropdown list within {Paul,Jhon}.

I'm using AngularJS, Node.js

I know that after getting every properties I have to apply unicity filter, to only have the differents properties but not the occurence

via Tewan