Structure navigation between two screens without losing data

I have a difficult to structure navigation between two screens without losing data

For example, i have a Screen called Person with any properties, and a second object called Functions, Person has multiple functions, and functions has other items inside their.

Example:

{
   "Person":{
      "Functions":[
         {
            "name":"test A",
            "subItems":[
               {
                  "test":"A"
               }
            ]
         }
      ]
   }
}

When I go to add a function, my person screen lose the data because i navigate to other URL, how to save the data without save in local/session storage, using database like as a temporary model, and identify when delete it?