When your input source contains attribute values that you would like to extract, here is one of many useful tips/hints from my colleague Louis Mau.
For example, in this figure below, we have a XML element "category" with the attribute "term" that you would like to extract the value "feed".
Do these steps:
1. To use the Transform operator
2. Create a XML element on the output side
3. Use the Function "Left Trim". Apply it to the Input tree XML attribute element.
As the result, you will get the associated value.