Return top N buckets only - elasticsearch

Question

So in elastic search I can do something like this:
{
"aggs": {
"title": {
"terms": {
"field": "title",
"shard_size": 50,
"size": 5
}
}
},
"query": {...},
"size": 0
}
And this will return me the document counts of the top 5 titles, so we end up with something like (in part):
"buckets" : [
{
"key" : "Delivery Driver",
"doc_count" : 1495
},
{
"key" : "Assistant Manager",
"doc_count" : 1250
},
{
"key" : "Server",
"doc_count" : 1175
},
{
"key" : "Dishwasher",
"doc_count" : 966
},
{
"key" : "Team Member",
"doc_count" : 960
}
]
But now I need to have the document counts in some custom buckets, so I do something like this:
{
"aggs": {
"loc": {
"filters": {
"filters": {
"1042_2": {
"terms": {
"counties": [
...
]
}
},
"1594_2": {
"terms": {
"counties": [
...
]
}
},
"1714_2": {
"terms": {
"counties": [
...
]
}
},
"1746_2": {
"terms": {
"counties": [
...
]
}
},
"1814_2": {
"terms": {
"counties": [
...
]
}
},
"1943_2": {
"terms": {
"counties": [
...
]
}
},
"2658_2": {
"terms": {
"counties": [
...
]
}
}
}
}
}
},
"query": {...},
"size": 0
}
Note that there are 7 buckets, because we don't know which are the largest. Running this will return us:
"buckets" : {
"1042_2" : {
"doc_count" : 23687
},
"1594_2" : {
"doc_count" : 8951
},
"1714_2" : {
"doc_count" : 52555
},
"1746_2" : {
"doc_count" : 60534
},
"1814_2" : {
"doc_count" : 63956
},
"1943_2" : {
"doc_count" : 25533
},
"2658_2" : {
"doc_count" : 534
}
}
But I would like it to only return me the largest 5 instead of all the buckets. Is there a way to restrict it to only the n largest buckets in the same way that the size parameter under terms did?

Answer 1

The size parameter does not make sense for filters aggregation, because by specifying the filters you already explicitly specify/control the number of buckets to get created and returned.
What you may want to consider though is, that you get all potential buckets created, but then get them sorted by descending count with an order-clause.
On client side then you simply "consume" the first n buckets.