Conditionally Hiding / Stopping a view from display
I would use a block, then create a tpl.php file for the block and inside it put

&lt;?php

$view = views_get_view('view_name_of_subcategory');
$view-&gt;set_display('block_1');
$view-&gt;execute();
        // results are now stored as an array in $view-&gt;result
$count = count( $view-&gt;result );

if ($count = 0) { print views_embed_view('view_name_of_products','block_2' } 
else { print $view-&gt;render(); }

?&gt;


Replace block_1 &amp; block_2 with your actual machine name, you can find it here (see picture)



PS if ($count = 0) does  not work try if ($count = null)