NextJS access a variable from another component

You need to use a global state management such as Redux (or Redux Toolkit!), or use React Context to share the variable.

I'm more familiar with redux toolkit (abbreviated as RTK). in RTK, you need to create a slice to manage a particular set of states.

For example lets assume your questions are for a quiz app, so using RTK, you can create a quiz slice like this

quizSlize.js

import { createSlice } from "@reduxjs/toolkit";

const initialState = {
   questions: [] // your initial questions
};

const quizSlice = createSlice({
  name: "quiz",
  initialState // this is equal to initialState: initialState,
  reducers: { // reducers are functions to mutate the state
    resetState: () => initialState,
    setQuestions: (state, action) => {
      state.questions = action.payload
    },
  },
});

export const _quiz = quizSlice.actions; //_quiz will be the object that stores all your reducers
export const $quiz = ({ quiz }) => quiz; //$quiz will be the object that stores all your variables
export default quizSlice.reducer;

after creating the slice you can use them in any component (after setting it up in the app of course)

using your example:

import {useDispatch, useSelector} from 'react-redux'
import {$quiz, _quiz} from './quizSlice'

function Questions() {
    const dispatch = useDispatch() // this is used to call the reducer
    const {question} = useState($quiz) // your variable

    const handleChange = event => {
        const target = event.target
        const name = target.name
        const value = target.value
        dispatch(_quiz.setQuestion(value))
    }
    ...

import {useSelector} from 'react-redux'
import {$quiz} from './quizSlice'

const Game = (index) => {
   // I want have acces at the 'question' variable
   const {question} = useSelector($quiz) // your variable
   //console.log(question)

   return (
       <div>
           <p className="text-white">{index.index.title}</p>
       </div>
   )
}

Hope this helps. for how to setup the RTK in your app, you can head to Redux toolkit on how to set it up, or find example apps

as react just send your variable through props

const passTheData = {}

<YourComponent data={passTheData} />

then in you component:

function YourComponent({data}){
  console.log(data)
}

import React, {useState} from "react"

const Game = ({theBigQuestion}) =>{
  console.log(theBigQuestion)
}

const Question = () =>{
  const [question, setQuestion] = useState("")
  const theQuestion = "C'est quoi la couleur de ton slip?"
  const handleChange = ()=>{
    setQuestion(theQuestion)
  }

  return (
    <Game theBigQuestion={question} />
  )
}

something like that