I have a SharePoint 2013 portal with search set up and crawled.  I can perform searches and get results.  I have a search center set up.  My problem is, I'm trying to use result sources to narrow a search to a particular shared document library or sub site. 

I set up a result source, set up a page under the search center, and associated the search center page with a search setting.  When I set up the query in the result source, it appears the test displays what I expect it to.  However, when I perform a search in the search center and select the source from the drop down, I still receive hits from the entire site collection. 

I should have stayed on 2007, or stopped at 2010, since search scopes worked perfectly fine *sigh*.

From within the Search Center, I went to Site Settings / Site Collection Administration / Search Result Sources.
I created a result source for my Information Technology page.  The query is local sharepoint, with the query transform being: path:http://server/it.  The results preview displays a list with 1716 items, and the preview shows just a handful of items, all falling under that particular site.  I can't advance to verify whether it's showing me items from another site. 

I then created a page in the search center, InfoTech.aspx.  Learned this has to be published, or the next step will fail.

I then went to Search Settings, and added a link to the Info Tech page created in the previous step.  The URL is /sites/search/pages/InfoTech.aspx. 

On the basic search center page, I can type in a word, and click the drop down menu, and select my "Info Tech" search source.  The results displayed have no affect on the selected source.  I get results from any site in the site collection.  Same result if I go to http://server/sites/search/pages/results.aspx and click Info Tech from below the search box. 

Here's a clue, possibly.  So, you arrive at the results page, and the box is populated with "ALL(*searchterm*).  Clicking the "Info Tech" link under the search box still shows "ALL(*SearchTerm*).  I'm not sure if that "ALL" should be replaced with some other verbiage. 

Try modifying the query transformation to Path:http://server/it*

Modified to Path:http://server/it*. Search results are still displayed for all sites in the collection. What's interesting is, I no longer have "ALL(*searchterm*)", rather, it now just displays "*searchterm" in the search bar.

On the "Build your query" dialog, if you click the TEST link, the full query text shows:

Path:http://server/it* -ContentClass-urn:content-class:SPSPeople

On the BASICS tab, the Query Text shows as:  Path:http://gnet/it*