Show text field after dropdown tag selection in blueprint, use for page that divides all pubic posts by tag

Hey all,
I’m making an archive page for a magazine. I’m having trouble with adding a field for an editors note for specific tags and for getting the result I want. Help would be very appreciated.

My idea is:

  1. The user goes on the archive panel page and selects ‘issue 1’ from a drop down, where all the currently available tags are shown.
  2. Upon selecting ‘issue 1’, a textarea field automatically appears below the dropdown. Here is where the editor can enter a note about the the posts tagged with ‘issue 1’.
  3. When the user saves the content of this text area, the blueprint automatically updates the archive page on website/archive to include a section that shows all posts tagged with ‘issue 1’, as well as the note that was just added.
  4. Repeating this with ‘issue 2’ or ‘issue n+’ etc, would add a section to the archive page.

I have so far:

 //Shows available tags
  width: 2/4
  label: Issue to Archive
  type: select
  options: query
  query: site.index.pluck("tags", ",", true)

//Shows test
  label: Editor's Note
  type: textarea
  minlength: 10
  maxlength: 500
  //how to show only when a valid tag was picked before hand?
  categories: query


//loop through all posts that are published
<?php $liveposts = $site->homePage()->children()->listed() ?>

//Separate posts by tag
Im not sure how to do this :(

//If post array of tag contains editor's note, then show in template
Im not sure how to do this :(

when only works with specific values, e.g.

    categories: issue-1

You would need a custom approach for this.

Yeah, I could not picture a way in which I could adjust the when: parameter.
Do you have any suggestions for where to look? I may have to hard code to start and craft a custom solution over time.

Wouldn’t it make more sense with a structure field with the select and a text field?

Was able to do it with structure field, thank you