How to add team to a Group?

look under Teams, then select to edit Bluebirds team, look to the right side for Details > Competitions and select the competitions (Group A B C) you want Bluebirds in.

yes, thx

Example for others:

Add a Primary League and after that add sub parent to it like
Group A, Group B

here is my code to display on a template page all Group teams like
Group A
team name 1
team name 2 etc.

<?php
/**
 * The template for displaying the Groupe Teams.
 *
 * Template Name: Grupe
 *
 * @package Rookie
 */

get_header(); ?>

	<div id="primary" class="content-area">
		<main id="main" class="site-main" role="main">

<?php
	$table_name = $wpdb->prefix . "term_taxonomy";
	$sql = "SELECT term_id FROM " . $table_name . " where parent!='0'";
	$pageposts = $wpdb->get_results($sql);

	foreach ( $pageposts as $pagepost)
	{	

			$table_name = $wpdb->prefix . "terms";
			$sql = "SELECT name FROM " . $table_name . " where term_id='".$pagepost->term_id."'";
			$ageposts = $wpdb->get_results($sql);
			foreach ( $ageposts as $agepost)
			{
				echo '<h4 class="sp-table-caption">'.$agepost->name.'</h4>';
			}

			echo '<table class="sp-data-table">';
			$table_name = $wpdb->prefix . "term_relationships";
			$sql = "SELECT object_id FROM " . $table_name . " where term_taxonomy_id='".$pagepost->term_id."'";
			$echipe = $wpdb->get_results($sql);
			foreach ( $echipe as $echipa)
			{

				$table_name = $wpdb->prefix . "posts";
				$sql = "SELECT post_title FROM " . $table_name . " where id='".$echipa->object_id."'";
				$nechipe = $wpdb->get_results($sql);
				foreach ( $nechipe as $nechipa)
				{
					echo '<tr><td>'.$nechipa->post_title.'</td></tr>';
				}

			}

			echo '</table>';
	}
?>

		</main><!-- #main -->
	</div><!-- #primary -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>

Edit: replace with this code, this is good:

<?php
/**
 * The template for displaying the homepage.
 *
 * Template Name: Grupe
 *
 * @package Rookie
 */

get_header(); ?>

	<div id="primary" class="content-area">
		<main id="main" class="site-main" role="main">

<?php
	$table_name = $wpdb->prefix . "term_taxonomy";
	$sql = "SELECT term_id FROM " . $table_name . " where parent!='0'";
	$pageposts = $wpdb->get_results($sql);

	foreach ( $pageposts as $pagepost)
	{	

			$table_name = $wpdb->prefix . "terms";
			$sql = "SELECT name FROM " . $table_name . " where term_id='".$pagepost->term_id."'";
			$ageposts = $wpdb->get_results($sql);
			foreach ( $ageposts as $agepost)
			{
				echo '<h4 class="sp-table-caption">'.$agepost->name.'</h4>';
			}

			echo '<table class="sp-data-table">';
			$table_name = $wpdb->prefix . "term_relationships";
			$sql = "SELECT object_id FROM " . $table_name . " where term_taxonomy_id='".$pagepost->term_id."'";
			$echipe = $wpdb->get_results($sql);
			foreach ( $echipe as $echipa)
			{

				$table_name = $wpdb->prefix . "posts";
				$sql = "SELECT post_title, guid FROM " . $table_name . " where post_type='sp_team' AND id='".$echipa->object_id."'";
				$nechipe = $wpdb->get_results($sql);
				foreach ( $nechipe as $nechipa)
				{
					echo '<tr><td>'.$nechipa->post_title.'</td></tr>';
					//echo '<tr><td><a>guid.'">'.$nechipa->post_title.'</a></td></tr>';
				}

			}

			echo '</table>';
	}
?>

		</main><!-- #main -->
	</div><!-- #primary -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>