Hello
I have problems to make a bar chart stacked, the data is with aggregations and the field that I need to stack is at the last level and I do not know how to obtain it.
I tried to flatten the structure but it did not work, I think I do not know how to do it.
I have the base of the bar graph armed with the groupings that I need.
I attach the data that give me the query and the vega
I would appreciate it if you could tell me how I can get the key of the last bucket
Result of query 
Data
Vega
{
"$schema": "https://vega.github.io/schema/vega-lite/v2.4.json",
"data": {
"url": {
"%context%": true,
"%timefield%": "caso_ts",
"index": "gdm_full",
"body": {
"size": 0,
"aggs": {
"cotizaciones": {
"terms": {
"field": "caso_S2_id.keyword",
"size": 500,
"order": {
"gestiones": "desc"
}
},
"aggs": {
"gestiones": {
"cardinality": {
"field": "ges_id.keyword"
}
},
"ultima_ges": {
"terms": {
"field": "ges_id.keyword",
"size": 1,
"order": {
"_term": "desc"
}
},
"aggs": {
"ges_ultima": {
"cardinality": {
"field": "ges_id.keyword"
}
},
"res_ultima_ges": {
"terms": {
"field": "ges_resultado_llamada.keyword",
"size": 10
},
"aggs": {
"res_ultima": {
"cardinality": {
"field": "ges_id.keyword"
}
}
}
}
}
}
}
}
}
}
},
"format": {
"property": "aggregations.cotizaciones.buckets"
}
},
"transform": [
{
"type": "flatten",
"fields": ["['ultima_ges']['buckets']"],
"as":["key"]
},
{
"type": "flatten",
"fields": ["['ultima_ges_buckets.key']"],
"as":["key2"]
},
{
"aggregate": [
{
"op": "count",
"field": "key",
"as": "cotizacionescount"
}
],
"groupby": [
"gestiones.value"
]
}
],
"encoding": {
"x": {
"field": "gestiones\\.value",
"type": "ordinal",
"sort": "descending"
},
"y": {
"field": "cotizacionescount",
"type": "quantitative"
}
},
"layer": [
{
"mark": "bar",
"encoding": {
"y": {
"field": "cotizacionescount",
"type": "quantitative",
"stack": "zero"
},
"x": {
"field": "gestiones\\.value",
"type": "ordinal",
"sort": "descending"
},
"color": {
"field": "key",
"type": "nominal"
}
}
},
{
"mark": {
"type": "text",
"align": "center",
"baseline": "bottom",
"dx": 0
},
"encoding": {
"x": {
"field": "gestiones\\.value",
"type": "ordinal",
"sort": "descending"
},
"y": {
"field": "cotizacionescount",
"type": "quantitative",
"stack": "zero"
},
"color": {
"field": "",
"type": "nominal",
"scale": {
"range": [
"white"
]
},
"legend": null
},
"text": {
"field": "cotizacionescount",
"type": "quantitative",
"format": ""
}
}
}
]
