Help with bundling search results

[MartinKip (Martin)]

Hello,

I am having trouble finding out if and how the following use case can be done with ElasticSearch.

I have an elastic cluster index with Real Estate properties. Some of these properties are the same property, but originate from a different source.
For example, the following 3 properties. The first and the last property are the same property (as can be seen by the BundleID), but are from different sources.
Note that sources have different reliability scores.

{
	"BundleID": "abcdef",
	"Address": "Streetname 18",
	"Price": 140000,
	"Source": "source_a",
	"SourceReliability": 100
},
{
	"BundleID": "qwert",
	"Address": "Other street 5",
	"Price": 300000,
	"Source": "source_a",
	"SourceReliability": 100
},
{
	"BundleID": "abcdef",
	"Address": "Streetname 18",
	"Price": 160000,
	"Source": "source_b",
	"SourceReliability": 20
}

Now comes the issue:
I only want to return the property in a bundle with the highest reliability score.
Not all users are allowed to search from all sources. So, imagine 3 users perform the same search request, searching for all available properties.

User 1 (may search in source_a AND source_b). The first and the second property should be returned. (the last should not be returned, because the first property is in the same bundle but has a higher reliability score)
User 2 (may search in source_a). The first two properties should be returned.
User 3 (may search in source_b). Only the last property should be returned.

So, as you may notice, most difficult part of this use case is the bundling together of documents with the same BundleID.
I have tried to generate Term aggregates on the BundleID and then return the first value using top_hits. But, when using this technique, I am not able to Sort the returned buckets. If I want my results to be returned sorted by
address, this is not possible (as far as I know).

Another thing I have tried is using the following objects:

{
	"BundleID": "abcdef",
	"Address": "Streetname 18"
	"properties": [
		{
			"Price": 140000,
			"Source": "source_a",
			"SourceReliability": 100
		},
		{
			"Price": 160000,
			"Source": "source_b",
			"SourceReliability": 20
		}
	]
},
{
	"BundleID": "qwert",
	"Address": "Other street 5",
	"properties": [
		{
			"Price": 300000,
			"Source": "source_a",
			"SourceReliability": 100
		}
	]
}

So, I have bundled the properties in my index, so I don't have to group the results using the query. But, this leads to the following issue:
User 2 (that could only search in source_a), is not allowed to search in the property for source_b. So, when this user searches all properties with a price higher than 150000, both properties are returned.
But, this is not allowed, because the first property is returned because a value from source_b matches.

Can anybody help me with this issue? Is there a query that can handle my use case? Or, should I change my document objects perhaps?

Thanks in advance.

With kind regards,
Martin