установка

npm i vuex-router-sync-previous

создание плагина

// plugins/vuex-router-sync.js
import { sync } from 'vuex-router-sync-previous'
export default ({app: {store, router}}) => {
  sync(store, router)
}

подключение

// nuxt.config.js
plugins: [
    { src: '~/plugins/vuex-router-sync.js' }
  ],

юзаем

store.state.route.path   // current path (string) 
store.state.route.params // current params (object) 
store.state.route.query  // current query (object) 

store.state.previousRoute.path // previous path (string) 
store.state.previousRoute.params // previous params (object) 
store.state.previousRoute.query // previous query (object)