Fillter array by key

I have a simple question, I did it in javascript, but in php everything is different:
In my request when I did dd($request->all()) it returned an array like this

$request = [
  'question_ru' => 'question ru',
  'asnwer_ru' => 'answer ru',
  'question_uz' => 'question uz',
  'asnwer_uz' => 'answer uz',
  'question_en' => 'question en',
  'asnwer_en' => 'answer en',
];

Now my problem is, I need to write a function which gets two argument: 1) a request, 2) a key and returns an array like this

function filter_array_by_key($array, $key) {}

function filter_array_by_key($request, 'title') =>

$result = [
  'title' => [
    'ru' => 'question ru',
    'uz' => 'question uz',
    'en' => 'question en',
  ],
];

‘JS VERSION’

export function filterFormDataByKey(object: Object, key: string) {
  let startNumber = key.length + 1
  const data = lodash.entries(object)

  let filteredObject = {}

  data.forEach((arr) => {
    if (arr[0].startsWith(key)) {
      let innerObj = { [arr[0].slice(startNumber)]: arr[1] }

      Object.assign(filteredObject, innerObj)
    }
  })

  return filteredObject
}

and it worked well!