It can be accessed under the Smile ElasticSuite menu, via the Search Relevance > Thesaurus configuration entry.

You can manage several parameters here.

General Configuration

Parameter	Default value	Description
Max Allowed Rewrites	2	Defines the maximum number of thesaurus rules applied simultaneously to a single search query to generate alternative queries. This limit applies first to synonym rules, and then to expansion rules. Example: If set to 2, each alternative query is built using at most 2 synonym rules and 2 expansion rules. ⚠️ Warning: Be cautious when increasing this value. If you have many rules with long lists of alternative terms, they could combine exponentially and significantly impact search performance.
Max Alternative Search Queries	50	Defines the absolute maximum number of alternative, rewritten search queries the engine will generate and process for a single user search. If you experience “max boolean clauses” errors from your Elasticsearch/OpenSearch cluster, or performance degradation due to a massive volume of active thesaurus rules (or from having stemming enabled for the thesaurus), you should lower this value. (Note: In older versions, this defaulted to 0, meaning no limitation).

Synonyms configuration

This panel contains base fulltext configuration settings.

Parameter	Default value	Description
Enable synonyms search	Yes	If the engine should generate “extended queries” based on the list of synonyms.
Synonyms weight divider	10	The way to calculate documents scores. A value of 10 means the score of documents matched by synonyms will be divided by 10.

Query Expansions Configuration

Parameter	Default value	Description
Enable search expansions	Yes	If the engine should generate “extended queries” baseds on the list of expansion terms.
Concepts weight divider	10	The way to calculate documents scores. A value of 10 means the score of documents matched by expansions will be divided by 10.