Hi @rotation,
That’s not currently possible, the next and previous feature is Wordpress default functionality and it’s used for navigating next or previous items. The gallery collections have no connection to portfolio items, it’s only used to display them.
But, if you mean by collection as portfolio category then it’s possible by adding this code to child theme’s functions.php
function x_entry_navigation() {
$stack = x_get_stack();
if ( $stack == 'ethos' ) {
$left_icon = '<i class="x-icon-chevron-left" data-x-icon-s=""></i>';
$right_icon = '<i class="x-icon-chevron-right" data-x-icon-s=""></i>';
} else {
$left_icon = '<i class="x-icon-arrow-left" data-x-icon-s=""></i>';
$right_icon = '<i class="x-icon-arrow-right" data-x-icon-s=""></i>';
}
$is_ltr = ! is_rtl();
$prev_post = get_adjacent_post( true, '', false, 'portfolio-category' );
$next_post = get_adjacent_post( true, '', true, 'portfolio-category' );
$prev_icon = ( $is_ltr ) ? $left_icon : $right_icon;
$next_icon = ( $is_ltr ) ? $right_icon : $left_icon;
?>
<div class="x-nav-articles">
<?php if ( $prev_post ) : ?>
<a href="<?php echo get_permalink( $prev_post ); ?>" title="<?php __( 'Previous Post', '__x__' ); ?>" class="prev">
<?php echo $prev_icon; ?>
</a>
<?php endif; ?>
<?php if ( $next_post ) : ?>
<a href="<?php echo get_permalink( $next_post ); ?>" title="<?php __( 'Next Post', '__x__' ); ?>" class="next">
<?php echo $next_icon; ?>
</a>
<?php endif; ?>
</div>
<?php
}
It should work if you have no other existing customization related to it. Please note that we don’t maintain and provider support for custom code like this, this should only serve as your starting point and the idea on how to achieve it.
Thanks!