Depivot json with different number of attributes

How does one depivot a json file that has two different categories, with some shared and some unshared attributes that leads to different attribute counts? 

Does one have to split the file before de-pivoting or is there a better way of selecting the attributed for de-pivoting?

I have attached the process as well as the json file. 

<?xml version="1.0" encoding="UTF-8"?><process version="9.7.002">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="9.4.000" expanded="true" name="Process">
    <parameter key="logverbosity" value="init"/>
    <parameter key="random_seed" value="2001"/>
    <parameter key="send_mail" value="never"/>
    <parameter key="notification_email" value=""/>
    <parameter key="process_duration_for_mail" value="30"/>
    <parameter key="encoding" value="SYSTEM"/>
    <process expanded="true">
      <operator activated="true" class="text:read_document" compatibility="9.3.001" expanded="true" height="68" name="Read Document" width="90" x="112" y="34">
        <parameter key="file" value="/Users/robinmeisel/Dropbox/Ornico/Instagram/json/radioawards.json"/>
        <parameter key="extract_text_only" value="true"/>
        <parameter key="use_file_extension_as_type" value="true"/>
        <parameter key="content_type" value="txt"/>
        <parameter key="encoding" value="SYSTEM"/>
      </operator>
      <operator activated="true" class="text:json_to_data" compatibility="9.3.001" expanded="true" height="82" name="JSON To Data" width="90" x="246" y="34">
        <parameter key="ignore_arrays" value="false"/>
        <parameter key="limit_attributes" value="false"/>
        <parameter key="skip_invalid_documents" value="false"/>
        <parameter key="guess_data_types" value="true"/>
        <parameter key="keep_missing_attributes" value="false"/>
        <parameter key="missing_values_aliases" value=", null, NaN, missing"/>
      </operator>
      <operator activated="true" class="de_pivot" compatibility="9.7.002" expanded="true" height="82" name="De-Pivot (5)" width="90" x="380" y="34">
        <list key="attribute_name">
          <parameter key="comment" value=".*edge_media_to_comment.*"/>
          <parameter key="text" value=".*edge_media_to_caption.*"/>
          <parameter key="liked" value=".*edge_liked_by.*"/>
          <parameter key="name" value=".*node.owner.username.*"/>
          <parameter key="url" value=".*node.display_url.*"/>
        </list>
        <parameter key="index_attribute" value="id"/>
        <parameter key="create_nominal_index" value="false"/>
        <parameter key="keep_missings" value="false"/>
      </operator>
      <connect from_op="Read Document" from_port="output" to_op="JSON To Data" to_port="documents 1"/>
      <connect from_op="JSON To Data" from_port="example set" to_op="De-Pivot (5)" to_port="example set input"/>
      <connect from_op="De-Pivot (5)" from_port="example set output" to_port="result 1"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
    </process>
  </operator>
</process>