finder.js

function finder(obj, keyToFind, level=7, soFar='', searched=new Set) {
  if (level<=0 || typeof obj != 'object' || obj === null || searched.has(obj)) return;
  searched.add(obj)
  
  if (keyToFind in obj) {
     console.log(soFar + '.' + keyToFind)
  }

  for (let key in obj) {
     try {
        finder(obj[key], keyToFind, level-1, soFar + '.' + key, searched);
     }
     catch(e) {}
  }
}