You can view the most shared content on a particular topic from a specific site by using the domain filter or the search bar.
To use the domain filter, enter your topic in the search bar and then use the 'Filter Domains' menu and enter your domain in the 'Include' field.
You can include more than one domain in your search by putting a comma after the first domain and then adding the second domain.
To use the search bar, enter the domain followed by the topic.
Note that the search bar can only be used for a single domain topic search.