Profile: Paul

Problem: I would like to programmatically assign a Content Template to imported posts.

Solution: Content Template assignment is defined by a hidden custom field "_views_template" that holds the ID of the Content Template to apply to a given post. You can use the save_post hook to apply this value automatically whenever a post is saved:

function save_book_meta( $post_id, $post, $update ) {
 
    $post_type = get_post_type($post_id);
 
    // If this isn't a 'book' post, don't update it.
    if ( "book" != $post_type ) return;
 
    // - Update the post's metadata.
    update_post_meta( $post_id, '_views_template', 12345 );
}
add_action( 'save_post', 'save_book_meta', 10, 3 );

Relevant Documentation:
https://codex.wordpress.org/Plugin_API/Action_Reference/save_post

Problem: I would like to show a View of taxonomy terms that are child terms of a specific parent term

Solution:
Here's how you can set this up:
1. Create a View of the taxonomy and add a Query Filter, filtered by term parent, where term parent is "None". This View will show the top-level terms in the term hierarchy. In the loop of this View, insert the term title or term link.
2. Create another View of the same taxonomy, again filtered by term parent, but this time where the term parent is set by the parent taxonomy View. In the loop of this View, insert the term title or term link.
3. Return to the first View and in the Loop after the term title, insert View 2.
4. Place View 1 on a custom Page somewhere to test it out.

Relevant Documentation:
https://toolset.com/documentation/user-guides/filtering-views-by-taxonomy/
https://toolset.com/documentation/user-guides/using-a-child-view-in-a-taxonomy-view-layout/
https://toolset.com/documentation/user-guides/passing-arguments-to-views/
https://toolset.com/documentation/user-guides/filtering-posts-by-user-selected-taxonomy/