Dialogflow CX / Vertex AI Search filter returns null for fields (size, structured_description.floor_level) despite schema being Indexable: true

[Panoptes_360_Virtual]

Good afternoon! I hope this post finds you well.

I am using a Dialogflow CX Data Store (backed by Vertex AI Search) to store JSON structured data with provided id’s, that i made, for property listings. When I try to use the filter parameter in the “Detect Intent” API, my queries return null (or an empty result set), even though the data exists and my schema appears to be configured correctly.

My JSON Document Here is a sample document that I have ingested into the data store:

{
  "p_id": 112970,
  "type": "Διαμέρισμα",
  "structured_description": {
    "proximity": [
      "πλησίον σχολείο (έως 500μ)",
      "πλησίον αγορά (έως 100μ)",
      "πλησίον μετρό/ηλεκτρικός (έως 500μ)"
    ],
    "heating_type": "πετρέλαιο",
    "construction_year": 1969,
    "extracted_bedrooms": 1,
    "energy_class": "Ζ",
    "floor_level": "1ος",
    "features": [
      "βεράντες",
      "διπλά τζάμια",
      "πόρτα ασφαλείας",
      "internet",
      "δορυφορική σύνδεση",
      "τέντες",
      "πατάρι"
    ]
  },
  "size": 57,
  "keys": 70,
  "creation_date": "10.01.2025",
  "address": "abc 123",
  "city": "Αμπελόκηποι (Αττική - Αθήνα Κέντρο)",
  "price": 1
}

What I’ve Tried

I am using the Dialogflow CX test console (or API) to send a filter query.

Test 1: Filter with Nested Field

This query attempts to filter by city, the nested floor_level, and type,

INPUT:

{
    "userMetadata": {},
    "filter": "city = \"Αμπελόκηποι (Αττική - Αθήνα Κέντρο)\" AND structured_description.floor_level = \"1ος\" AND type = \"Διαμέρισμα\"",
    "query": "",
    "fallback": ""
}

OR I thought that since structured_description is an object, google cloud data connector classifies it as non searchable, indexable etc and thus I thought that the children inside it like

floor_level

even though they are searchable, indexable etc. since the parent is not they would not appear. Thus I put size into the equation and still fails.

{
    "userMetadata": {},
    "filter": "city = \"Αμπελόκηποι (Αττική - Αθήνα Κέντρο)\" AND size = 57",
    "query": "",
    "fallback": ""
}

Both of those input return null output, while searching just a normal query for the id 112970 works!

I am also attaching the screenshot from google cloud connector
Lastly, please let me know about how to use parameter’s and if there is an online guide available.