Hi,
HikaShop have a trigger
function onBeforeProductListingLoad(&$filters, &$order, &$view, &$select, &$select2, &$ON_a, &$ON_b, &$ON_c)
The parameter $view is the view object. But the $view can be a module.
You can check it with the code:
if($view->module) { /* ... */ }
HikaMarket uses this trigger to make the sync for the product listing modules on the vendor page.
You can find the code in the plugin "market" and the rest of the code in the class "product".
You can write a little plugin which will check the current "ctrl" (like in the hikamarket product class, function processListing) and apply a vendor filter thanks to the current viewing product.
It means that you will have to load the current product to get his vendor id and apply the filter.
The code in the hikamarket product class should help you, giving you an important part of the code. It just need some little customization and put it into a plugin (to keep your feature with HikaShop/HikaMarket updates).
Regards,