[Vuejs]-How to access the current instance in nuxt page validate()?

Its not possible. Validate executed before the instance initialized, so you cant access methods. And validate isnt supposed to be used that way.

For passing data to need either to save them into vuex store ( preferably in fetch method ) or return them as data in asyncData method. Then you can do what you want with your data in for example mounted method, or beforeMounted.