Add getter for path field in NestedQueryBuilder (opensearch-project#4636

)

(cherry picked from commit 7b7ca98)
Signed-off-by: psmagin <pavlo_smahin@epam.com>

CHANGELOG.md

@@ -34,6 +34,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [BWC and API enforcement] Introduce checks for enforcing the API restrictions ([#11175](https://github.com/opensearch-project/OpenSearch/pull/11175))
 - Maintainer approval check ([#11378](https://github.com/opensearch-project/OpenSearch/pull/11378))
 - Create separate transport action for render search template action ([#11170](https://github.com/opensearch-project/OpenSearch/pull/11170))
+- Add getter for path field in NestedQueryBuilder ([#4636](https://github.com/opensearch-project/OpenSearch/pull/4636))
 
 ### Dependencies
 - Bumps jetty version to 9.4.52.v20230823 to fix GMS-2023-1857 ([#9822](https://github.com/opensearch-project/OpenSearch/pull/9822))

server/src/main/java/org/opensearch/index/query/NestedQueryBuilder.java

@@ -130,6 +130,13 @@ protected void doWriteTo(StreamOutput out) throws IOException {
         out.writeBoolean(ignoreUnmapped);
     }
 
+    /**
+     * Returns path of the nested query.
+     */
+    public String path() {
+        return path;
+    }
+
     /**
      * Returns the nested query to execute.
      */

server/src/test/java/org/opensearch/index/query/NestedQueryBuilderTests.java

@@ -146,6 +146,10 @@ public void testSerializationBWC() throws IOException {
         }
     }
 
+    public void testPath() {
+        assertEquals("nested1", createTestQueryBuilder().path());
+    }
+
     public void testValidate() {
         QueryBuilder innerQuery = RandomQueryBuilder.createQuery(random());
         IllegalArgumentException e = expectThrows(