This might be a feature request, but I did expect the same. 1) Open a PDF "greatPaper" in Zotero 2) Add a note to this PDF 3) Add a tag "myTag" to the note 4) Go to the library 5) Select the tag "myTag" in the bottom left search 6) I would expect "greatPaper" to be shown, but it isn't because the tag isn't connected to the PDF. The tag is just connected to the note
@ben.meier: Not clear what you mean by "note" here. If you're referring to PDF annotations, that's unrelated to this thread. Annotation tags aren't yet used in the main library view, but they will be shortly.
1) Open a PDF "greatPaper" in Zotero
2) Add a note to this PDF
3) Add a tag "myTag" to the note
4) Go to the library
5) Select the tag "myTag" in the bottom left search
6) I would expect "greatPaper" to be shown, but it isn't because the tag isn't connected to the PDF. The tag is just connected to the note