Please follow this link
https://aftabablog.wordpress.com/2016/06/16/how-to-create-a-custom-filter-in-wp/
Hope this will give you idea on how to create custom filter based on meta query
Please follow this link
https://aftabablog.wordpress.com/2016/06/16/how-to-create-a-custom-filter-in-wp/
Hope this will give you idea on how to create custom filter based on meta query