Sub-aggregation or aggregation filter in elastic - elasticsearch

Question

I have a list of records with name and timestamp. For each name, I want to get the maximal timestamp, but I only want to get names with max timestamp before an hour ago (meaning that in my result I would only like to see a list of names and their max timestamp, but only for names that has max timestamp before an hour ago. If a name has a record with timestamp after an hour ago, I don't want to see this name in my result).
I tried to solve this issue using aggregation, by creating a term aggregation over name, and then aggregating over max timestamp and then filtering records with max timestamp after one hour ago, as follows:
{
"size": 0,
"aggs": {
"names_aggs": {
"terms": {
"field": "name",
"size": 10
},
"aggs": {
"max_timestamp": {
"max": {
"field": "timestamp"
},
"aggs": {
"sub-agg": {
"filter": {
"range": {
"timestamp": {
"lt": "now-1h"
}
}
}
}
}
}
}
}
}
}
However, this query produces the following error:
{
"type": "aggregation_initialization_exception",
"reason": "Aggregator [max_timestamp] of type [max] cannot accept sub-aggregations"
}
I can basically get a similar functionality by using the timestamp filter before the max aggregation as follows:
{
"size": 0,
"aggs": {
"names_aggs": {
"terms": {
"field": "name",
"size": 10
},
"aggs": {
"maximals": {
"filter": {
"range": {
"timestamp": {
"lt": "now-1h"
}
}
},
"aggs": {
"max_timestamp": {
"max": {
"field": "timestamp"
}
}
}
}
}
}
}
}
Indeed, I get a set of results with name and max_timestamp for each name that passed the maximals filter, and a null max_timestamp for each name that didn't pass the maximals filter. This is a solution I can work with, however, this query does not return for a large amount of records, because of the maximals filter that runs for each name.
Thanks in advance for your help.