With the advanced Filters you are able to filter products from your feed based on values from product source fields. This way you are able to exclude products based on any product source like Product id or SKU number.
Create product filters to exclude products
A good use for this function is that you could use regular price to exclude product with a price below a given amount. This way you can exclude products that will not be profitable enough to include.
To ad filters to your feed click the (edit) link underneath the category mapping section where is says: “All products from the selected Shop Categories will be included in the feed”.
A row with drop downs wil present it self where you can use product source field values to determine what products should be excluded.