get_subcategory_terms

functions.php

<?php 

function get_subcategory_terms( $terms, $taxonomies, $args ) {
 
	$new_terms 	= array();
	$hide_category 	= array( 300 );  // 300 is the category id, replace it with yours
 	
 	  // if a product category and on the shop page
	if ( in_array( 'product_cat', $taxonomies ) && !is_admin() && is_shop() ) {
	    foreach ( $terms as $key => $term ) {
		if ( ! in_array( $term->term_id, $hide_category ) ) { 
			$new_terms[] = $term;
		}
	    }
	    $terms = $new_terms;
	}
  return $terms;
}
add_filter( 'get_terms', 'get_subcategory_terms', 10, 3 );