Add documentation for using rerank and normalization processors toget…

…her (opensearch-project#7513)

* Add documentation for using rerank and normalization processors together

Signed-off-by: Fanit Kolchina <[email protected]>

* Update _search-plugins/search-relevance/reranking-search-results.md

Co-authored-by: Nathan Bower <[email protected]>
Signed-off-by: kolchfa-aws <[email protected]>

---------

Signed-off-by: Fanit Kolchina <[email protected]>
Signed-off-by: kolchfa-aws <[email protected]>
Co-authored-by: Nathan Bower <[email protected]>
Signed-off-by: [email protected] <[email protected]>

_search-plugins/search-relevance/reranking-search-results.md

@@ -115,4 +115,19 @@ POST /my-index/_search
 ```
 {% include copy-curl.html %}
 
-Alternatively, you can provide the full path to the field containing the context. For more information, see [Rerank processor example]({{site.url}}{{site.baseurl}}/search-plugins/search-pipelines/rerank-processor/#example).
+Alternatively, you can provide the full path to the field containing the context. For more information, see [Rerank processor example]({{site.url}}{{site.baseurl}}/search-plugins/search-pipelines/rerank-processor/#example).
+
+## Using rerank and normalization processors together
+
+When you use a rerank processor in conjunction with a [normalization processor]({{site.url}}{{site.baseurl}}/search-plugins/search-pipelines/normalization-processor/) and a hybrid query, the rerank processor alters the final document scores. This is because the rerank processor operates after the normalization processor in the search pipeline.
+{: .note}
+
+The processing order is as follows: 
+
+- Normalization processor: This processor normalizes the document scores based on the configured normalization method. For more information, see [Normalization processor]({{site.url}}{{site.baseurl}}/search-plugins/search-pipelines/normalization-processor/).
+- Rerank processor: Following normalization, the rerank processor further adjusts the document scores. This adjustment can significantly impact the final ordering of search results.
+
+This processing order has the following implications:
+
+- Score modification: The rerank processor modifies the scores that were initially adjusted by the normalization processor, potentially leading to different ranking results than initially expected.
+- Hybrid queries: In the context of hybrid queries, where multiple types of queries and scoring mechanisms are combined, this behavior is particularly noteworthy. The combined scores from the initial query are normalized first and then reranked, resulting in a two-stage scoring modification.