Hello,
I am not sure how you specify the current manufacturers (search word?). However, you can pass the parameters e.g. by query string. 
Then you can for example create a custom macro (
documentation) which will return the string for Search filter’s 
Values according to current query strings. If you cause a postback it will update the Smart search filter. You can use the custom macro in 
Values property of Smart search filter which defines the filter criteria.
If you need a manufacturer’s name (not the ID) you can use API to know it. The API Reference is here: 
API Reference.
Best regards,
Helena Grulichova