A form with choice field, and when choice is set to true we show other 2 fields

 

Editor screenshots:

Configuration for 2 definition rules:

 

Storage format

<ac:structured-macro ac:macro-id="7beef769-5ecb-413d-86f1-2b606c9e7d8c" ac:name="confiform" ac:schema-version="1">
  <ac:parameter ac:name="formName">f1</ac:parameter>
  <ac:rich-text-body>
    <p>
      <ac:structured-macro ac:macro-id="f04f47db-852e-4b72-8a98-576b2df0ff83" ac:name="confiform-field-definition" ac:schema-version="1">
        <ac:parameter ac:name="fieldName">choice</ac:parameter>
        <ac:parameter ac:name="fieldLabel">My choice</ac:parameter>
        <ac:parameter ac:name="values">false[yes=Yes|no=No|]</ac:parameter>
        <ac:parameter ac:name="extras">id;false</ac:parameter>
        <ac:parameter ac:name="type">select</ac:parameter>
      </ac:structured-macro>
    </p>
    <p>
      <ac:structured-macro ac:macro-id="8d5c478c-6385-4a4b-b091-ede7b1706760" ac:name="confiform-field-definition" ac:schema-version="1">
        <ac:parameter ac:name="fieldName">mf1</ac:parameter>
        <ac:parameter ac:name="fieldLabel">My field1</ac:parameter>
        <ac:parameter ac:name="type">text</ac:parameter>
      </ac:structured-macro>
    </p>
    <p>
      <ac:structured-macro ac:macro-id="e0aedf78-e3af-4309-9c03-38a71cd6c7c4" ac:name="confiform-field-definition" ac:schema-version="1">
        <ac:parameter ac:name="fieldName">mf2</ac:parameter>
        <ac:parameter ac:name="fieldLabel">My Field 2</ac:parameter>
        <ac:parameter ac:name="type">text</ac:parameter>
      </ac:structured-macro>
      <ac:structured-macro ac:macro-id="c500d04f-59f8-4d25-9a1f-a92bb512159b" ac:name="confiform-entry-register" ac:schema-version="1">
        <ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter>
        <ac:rich-text-body>
          <p> </p>
        </ac:rich-text-body>
      </ac:structured-macro>
      <ac:structured-macro ac:macro-id="40e1e7e8-4f1d-4cc1-9555-15ab9853779c" ac:name="confiform-field-definition-rules" ac:schema-version="1">
        <ac:parameter ac:name="condition">choice: OR choice:no</ac:parameter>
        <ac:parameter ac:name="fieldName">mf1,mf2</ac:parameter>
        <ac:parameter ac:name="action">Hide field</ac:parameter>
        <ac:parameter ac:name="actionFieldName">choice</ac:parameter>
      </ac:structured-macro>
    </p>
    <p>
      <ac:structured-macro ac:macro-id="ac8e9df6-ff25-4cc3-97ff-10a5b0429634" ac:name="confiform-field-definition-rules" ac:schema-version="1">
        <ac:parameter ac:name="condition">choice:yes</ac:parameter>
        <ac:parameter ac:name="fieldName">mf1,mf2</ac:parameter>
        <ac:parameter ac:name="action">Show field</ac:parameter>
        <ac:parameter ac:name="actionFieldName">choice</ac:parameter>
      </ac:structured-macro>
    </p>
  </ac:rich-text-body>
</ac:structured-macro>