i have configured grafana to access elasticsearch 6.4.
i have created a graph, now i wan to have 4 list items which contain From Year, From Month, To Year and To Month.
i know i have to add variables to my page. i can add the whole field like below
it return the full date, i need to know the regular expression which i apply and it return distinct years from the field @timestamp.
then i need another regular expression to extract distinct months.
how i can do that?