Profile: hugoC-3

Problem:
how to display posts using views group by custom titles with different numbers of items

Solution:
You should create view's par section and use view's "Limit and Offset" section to limit the number of posts and skip the number of posts.

You can find proposed solution, in this case, with the following reply
https://toolset.com/forums/topic/loop-with-different-numbers-of-items/#post-852320

Relevant Documentation:

Problem: I would like to use a View to show information about a single post. I know the post ID and I would like to pass that ID into the View's filter using a shortcode attribute.

Solution: Use the Query Filter panel in the View editor screen to apply a filter by post ID, set by a shortcode attribute. Pass the desired post ID into the View shortcode using the standard attribute "ids", or modify the settings in the Query Filter to match a custom attribute you have already applied to your shortcode.

Relevant Documentation:
https://toolset.com/documentation/user-guides/filtering-views-query-by-post-id/
https://toolset.com/documentation/user-guides/passing-arguments-to-views/

Problem: I would like to create a View that shows posts that are associated to a specific term, but not its child terms.

Solution: Add the following custom code to your child theme's functions.php file:

add_filter( 'wpv_filter_query', 'only_term_filter',99,3 );
function only_term_filter( $query_args, $views_settings, $view_id) {
  $view_ids = [12345,67890];
  if (in_array($view_id, $views_ids)){
    foreach($query_args['tax_query'] as $tq) {
      if( isset( $tq['taxonomy'] ) ){
        $tax = $tq['taxonomy'];
        $term = get_term_by('id', $tq['terms'][0], $tax);
        $termChildren = get_term_children($term->term_id, $tax);
        $query_args['tax_query'][] = array(
          'taxonomy' => $tax,
          'field' => 'id',
          'terms' => $termChildren,
          'operator' => 'NOT IN'
        );
      }
    }
  }
  return $query_args;
}

Replace 12345,67890 with a comma-separated list of View IDs where you want to apply this filter. Make sure your View's taxonomy filter is set up to respond to a shortcode attribute, something like "wpvcategory". Then pass the top-level term slug into the shortcode attribute like this:

[wpv-view name="your-view-slug" wpvcategory="parent-term"]

The View will return posts with the top-level term applied, but no posts that have to its child terms.

Relevant Documentation:
https://toolset.com/documentation/user-guides/passing-arguments-to-views/
https://toolset.com/documentation/programmer-reference/views-filters/#wpv_filter_query