Add a column in event lists showing players by position

sp_event_list_players_by_position.php

<?php

/**
 * Example Usage.
 */
sp_event_list_players_by_position( 'team-1', 'Team 1' );
sp_event_list_players_by_position( 'team-2', 'Team 2' );
sp_event_list_players_by_position( 'team-3', 'Team 3' );
sp_event_list_players_by_position( 'team-4', 'Team 4' );

/**
 *  Add a column in event lists showing players by position.
 * @param  string $position_slug  Position slug, e.g. `goalkeeper`.
 * @param  string $label          Label for table header, e.g. `Goalkeeper`.
 * @param  string $team           `home` or `away`.
 */
function sp_event_list_players_by_position( $position_slug, $label, $team = 'home' ) {

	add_action( 'sportspress_event_list_head_row', function( $use_columns ) use ( $label ) {

		echo '<th>' . $label . '</th>';
	} );

	add_action( 'sportspress_event_list_row', function( $event, $use_columns ) use ( $team, $position_slug ) {

		/**
		 * Getting all team players
		 */
		$players_in_event = get_post_meta ( $event->ID, 'sp_players', true );
		$players_in_team = false;
		if ( is_array( $players_in_event ) ) {
			if ( 'home' == $team ) {
				$players_in_team = array_values( $players_in_event )[ 0 ];
			} else if ( 'away' == $team ) {
				$players_in_team = array_values( $players_in_event )[ 1 ];
			}
			unset( $players_in_team[ 0 ] );
		}

		/**
		 * Prepare output.
		 */
		$players_in_position = [];
		if ( $players_in_team ) {
			foreach ( $players_in_team as $player_id => $player ) {
				if ( array_key_exists( 'position', $player ) ) {
					$player_positions_terms = [];
					foreach( $player['position'] as $player_position_id) {
						$player_positions_terms[] = get_term( $player_position_id, 'sp_position' );
					}
					$player_positions_terms_matching = array_filter( $player_positions_terms, function( $position_term ) use ($position_slug) {
						return $position_term->slug === $position_slug;
					} );
					if( $player_positions_terms_matching ) {
						$players_in_position[] = get_the_title( $player_id );
					}
				}
			}
		}

		/**
		 * Output.
		 */
		echo '<td class="data-custom-' . $position_slug . '" data-label="' . $label . '">';
		echo implode( $players_in_position, '<hr>');
		echo '</td>';
	}, 10, 2 );
}