Final code for myCRED Tutorial - http://mycred.me/tutorial/buddypress-user-field-number-of-log-entries-to-show/

bp-user-field-rowshow

add_filter( 'mycred_bp_history_num_to_show', 'buddypress_number_of_rows_to_show' );
function buddypress_number_of_rows_to_show( $num ) {
	$user_id = bp_displayed_user_id();
	$number = xprofile_get_field_data( 'Your User Fields Title', $user_id );
	if ( ! empty( $number ) )
		return $number;
	
	return $num;
}