You can filter products based on their sellers by using this chrome extension. Download the extension as zip by clicking on 'Download ZIP' button. Extract it wherever you please.
To install the extension in Google Chrome, go to settings and click on extensions. Then, in upper right corner of window, tick mark the 'developer mode'. Now you need to drag and drop or browse to the location where you extracted the zip file.
If done correctly, extension with name "Flipkart Seller Filter" will appear in extension list.
Now just go to flipkart and press CTRL+F and search "Seller Filter" and you will see where the button is. Enter seller name (WS Retail) and give it some time.
The extension will highlight the products from the seller you entered. In your case, it is WS Retail.