With YITH Multi Vendor you can turn your e-commerce store into a marketplace (a multi-vendor platform) like Amazon or Etsy. Turn your e-commerce store into a marketplace (a multi-vendor platform) and earn commissions on orders generated by your vendors.
The integration between these two plugins allows users to enter the vendor’s name and instantly get a list of their products. To do that, all you need to do is install the plugin and activate it.
Then, go to YITH > Ajax Search > Search and enable the option Search by vendor.

Now, if you start typing the name of a vendor, the plugin will automatically show this vendor’s products.

For more details about YITH Multi Vendor, please, check the official documentation.