This is for data.gov and thanks for answering the question.
1Can you be more specific about the use you intend for the data? and what do you want to get out of the country level filtering - web pages or links to datasets or ...?– Marcus DJun 15, 2020 at 15:15
You may need to clarify your question to be more specific. But, if I understand correctly, you can filter by Organization Type and select "county government" on the left side of the page. https://catalog.data.gov/dataset#sec-organization_type