Refactor the copy_to mapping parameter documentation

_field-types/mapping-parameters/copy-to.md

@@ -10,74 +10,81 @@ has_toc: false
 
 # Copy to
 
-The `copy_to` parameter allows you to copy the values of multiple fields into a single field. This parameter can be useful if you often search across multiple fields because it allows you to search the group field instead. 
+The `copy_to` parameter allows you to copy the values of multiple fields into a group field, which can then be queried as a single field. This is useful when you frequently search across multiple fields and want to simplify your queries.
 
-Only the field value is copied and not the terms resulting from the analysis process. The original `_source` field remains unmodified, and the same value can be copied to multiple fields using the `copy_to` parameter. However, recursive copying through intermediary fields is not supported; instead, use `copy_to` directly from the originating field to multiple target fields.
+Note the following important considerations:
 
----
+- During copying, the raw field value (not the tokens produced during analysis) is copied.
+
+- The original `_source` field is not modified to reflect the copied values.
+
+- The same value can be copied to multiple fields using `"copy_to": ["field_1", "field_2"]` syntax.
+
+- You cannot copy recursively through intermediary fields. For example, if `field_1` is copied to `field_2` and `field_2` is copied to `field_3`, indexing into `field_1` does not result in values appearing in `field_3`. Instead, use `copy_to` directly from the originating field to multiple target fields.
 
 ## Examples
 
-The following example uses the `copy_to` parameter to search for products by their name and description and copy those values into a single field:
+The following examples demonstrate using the `copy_to` parameter.
+
+### Basic copy_to usage
+
+Create an index that copies first and last names into a `full_name` field:
 
 ```json
-PUT my-products-index
+PUT /user_profiles
 {
   "mappings": {
     "properties": {
-      "name": {
+      "first_name": {
         "type": "text",
-        "copy_to": "product_info"
+        "copy_to": "full_name"
       },
-      "description": {
+      "last_name": {
         "type": "text",
-        "copy_to": "product_info" 
+        "copy_to": "full_name"
       },
-      "product_info": {
+      "full_name": {
         "type": "text"
-      },
-      "price": {
-        "type": "float"
       }
     }
   }
 }
+```
+{% include copy-curl.html %}
 
-PUT my-products-index/_doc/1
-{
-  "name": "Wireless Headphones",
-  "description": "High-quality wireless headphones with noise cancellation",
-  "price": 99.99
-}
+Index a document with separate name fields:
 
-PUT my-products-index/_doc/2
+```json
+PUT /user_profiles/_doc/1
 {
-  "name": "Bluetooth Speaker",
-  "description": "Portable Bluetooth speaker with long battery life",
-  "price": 49.99
+  "first_name": "Jane",
+  "last_name": "Doe"
 }
 ```
 {% include copy-curl.html %}
 
-In this example, the values from the `name` and `description` fields are copied into the `product_info` field. You can now search for products by querying the `product_info` field, as follows:
+The `first_name` and `last_name` fields can still be queried individually, but the `full_name` field allows you to search for both names together. To search using the combined field, send the following request. The `and` operator requires both terms to match:
 
 ```json
-GET my-products-index/_search
+GET /user_profiles/_search
 {
   "query": {
     "match": {
-      "product_info": "wireless headphones"
+      "full_name": {
+        "query": "Jane Doe",
+        "operator": "and"
+      }
     }
   }
 }
 ```
 {% include copy-curl.html %}
 
-## Response
+The response contains the matching document:
 
 ```json
 {
-  "took": 20,
+  "took": 7,
   "timed_out": false,
   "_shards": {
     "total": 1,
@@ -90,20 +97,105 @@ GET my-products-index/_search
       "value": 1,
       "relation": "eq"
     },
-    "max_score": 1.9061546,
+    "max_score": 0.26152915,
     "hits": [
       {
-        "_index": "my-products-index",
+        "_index": "user_profiles",
         "_id": "1",
-        "_score": 1.9061546,
+        "_score": 0.26152915,
         "_source": {
-          "name": "Wireless Headphones",
-          "description": "High-quality wireless headphones with noise cancellation",
-          "price": 99.99
+          "first_name": "Jane",
+          "last_name": "Doe"
         }
       }
     ]
   }
 }
 ```
 
+### Copying to multiple target fields
+
+To copy the field contents to multiple target fields, create an index that copies the `title` field into both the `searchable_content` and `display_text` fields. The `body` field is copied only to `searchable_content`:
+
+```json
+PUT /content_library
+{
+  "mappings": {
+    "properties": {
+      "title": {
+        "type": "text",
+        "copy_to": ["searchable_content", "display_text"]
+      },
+      "body": {
+        "type": "text",
+        "copy_to": "searchable_content"
+      },
+      "searchable_content": {
+        "type": "text"
+      },
+      "display_text": {
+        "type": "text"
+      }
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+Index a document containing the `title` and `body` fields:
+
+```json
+PUT /content_library/_doc/1
+{
+  "title": "OpenSearch Documentation Guide",
+  "body": "This comprehensive guide covers mapping parameters and their usage in OpenSearch."
+}
+```
+{% include copy-curl.html %}
+
+You can search both title and body content using the `searchable_content` field:
+
+```json
+GET /content_library/_search
+{
+  "query": {
+    "match": {
+      "searchable_content": "OpenSearch mapping parameters"
+    }
+  }
+}
+```
+{% include copy-curl.html %}
+
+The response contains the matching document. The document's original `_source` field still contains only the `title` and `body` fields:
+
+```json
+{
+  "took": 21,
+  "timed_out": false,
+  "_shards": {
+    "total": 1,
+    "successful": 1,
+    "skipped": 0,
+    "failed": 0
+  },
+  "hits": {
+    "total": {
+      "value": 1,
+      "relation": "eq"
+    },
+    "max_score": 0.44133043,
+    "hits": [
+      {
+        "_index": "content_library",
+        "_id": "1",
+        "_score": 0.44133043,
+        "_source": {
+          "title": "OpenSearch Documentation Guide",
+          "body": "This comprehensive guide covers mapping parameters and their usage in OpenSearch."
+        }
+      }
+    ]
+  }
+}
+```