How can read a nested json Map in StepFunction parameter

1."ItemsPath": "$.requestPayload.files": This selects the "files" key from the JSON map located at the path "$.requestPayload.files."

2. "ItemSelector": { ... }: The ItemSelector is a set of expressions to access specific keys or values from the selected map element.

3. "requestPayload.context.$": "$.requestPayload.context": This accesses the value of the "context" key from the JSON map located at the path "$.requestPayload.context."

4. "dataset.$": "$.[0][$$.Map.Item.Value]": This selects the first element from the array, which is the current element being processed in the map (specified by "$.[0]"), and then accesses the value based on the key specified by "$$$.Map.Item.Value" (the key in the map being processed).

5. "file.$": "$$$.Map.Item.Value": This directly accesses the value of the current key being processed in the map ("$$$.Map.Item.Value").

With these expressions, you can read and access the keys "Dataset1" and "Dataset2" from the JSON map within the StepFunction parameter.