How to visulize two level of aggregation in kibana?

I have a document type in Elasticsearch.
doc1
{
event_timestamp="2019-06-05 13:56:45"
event_type="heart_beat"
store_id="abc"
}
I want to aggregate on two levels first on hours and then on days. Is it possible to do in Kibana? I want to (count number of hours in a day) =A in which at least one "heartbeat" event has come. then I want to find cumulative sum of A for a range of days. and divide that sum by 24*(number of days in range).
for particular store_id

What have you tried so far? I'm trying to figure out if a Pipeline aggregation over a Sum Bucket might work? Maybe Moving Average?