Content filter

What do you mean on “filter”? Please be more specific.

I want to syndicate a specific topic (i.e. Health) instead of the full feed.

Is that a WordPress feed? If so, you can pull it by specified categories or tags. E.g. if the source feed looks like this:

https://www.somefeed.com/feed/

You can take only a specific category from it:

https://www.somefeed.com/category/health/feed/

or a tag:

https://www.somefeed.com/tag/health/feed/

No, it’s RSS feeds from newspapers likes these ones:

https://www.journaldemontreal.com/rss.xml
https://www.lactualite.com/feed/
https://rss.radio-canada.ca/fils/nouvelles/nouvelles.xml
https://www.tvanouvelles.ca/rss.xml

I was using FeedWordPress with advanced filters but not more developed.

In this case I can suggest only CyberSEO, which can do it, but it’ a premium plugin.

I took a look recently at CyberSEO and did not see this feature in the list.

It does allow custom coding, so almost any task could be done by means of a simple PHP snippet. There are many various solutions on the support forum. Like how to import only those posts that have the specified keywords/tags/categories or how to skip the posts that have “banned” keywords etc.