Q:

Searching by views

Searching is hard to completely understand using SharePoint 2013.
Is there a way to restrict search results to come from a certain view in document library?
It is possible to build a query?
I am thinking that I can restrict by Tag to make this happen, but I am not sure.
Is it possible to produce search results from a certain view?  

A:

Yes, you can.
Try adding a search results webpart to you page, and edit the properties.
Then click on "change query". You can specify a tag there. 

 If you use SharePoint 2013 Enterprise you can also you the CSWP.

Also you can do much more via the advanced view (Switch to Advanced Mode):

