Active Admin - adding custom search(outside the resource model)

In ActiveAdmin, if your resource model is deriving some data from other models, using some kind of relationship(has_one or has_many). In this scenarios where you want to search and filter the resource based on the data in its related table, you can follow below: Suppose you have a model School, and a model Student, now you want to search or filter students based on the school name. We can filter using join(:schools).where("schools.name like") or say an In Query which is inefficient. Either way ActiveAdmin does not provide default filters based on