add composite sources seoperate metadata fields

Author: Deepthi-Chand

api/views/paginated_elastic_view.py

@@ -91,7 +91,7 @@ def get(self, request: HttpRequest) -> Response:
             aggregations.pop("metadata")
             for agg in metadata_aggregations:
                 label: str = agg["key"]["metadata_label"]
-                value: str = agg["key"]["metadata_value"]
+                value: str = agg["key"].get("metadata_value", "")
                 if label not in aggregations:
                     aggregations[label] = {}
                 aggregations[label][value] = agg["doc_count"]

api/views/search_dataset.py

@@ -169,7 +169,12 @@ def add_aggregations(self, search: Search) -> Search:
 
             metadata_bucket = search.aggs.bucket("metadata", "nested", path="metadata")
             composite_sources = [
-                {"metadata": {"terms": {"field": "metadata.label.keyword"}}}
+                {
+                    "metadata_label": {
+                        "terms": {"field": "metadata.metadata_item.label"}
+                    }
+                },
+                {"metadata_value": {"terms": {"field": "metadata.value"}}},
             ]
             composite_agg = A(
                 "composite",