Bourbaki style "relative"/"conditional" referencing

Question

Is there a way to reference the labelled things via their "relative" paths? (This is how Bourbaki referenced in their books.)

More precisely, I am using the book with chapters, sections and subsections. To maintain simplicity, assume that everything is numbered. The following cases illustrate what I want:

1. References to Chapter 1 from within the same chapter should be "this chapter" and those from other places should be "Chapter 1".
2. References to Chapter 1's Section 2 from within the same section should be "this section", those from Chapter 1's any other places within Chapter 1 should be "Section 2", and those from the remaining paces should be "Section 2 of Chapter 1".
3. References to Chapter 1's Section 2's Subsection 3 from within the same subsection should be "this subsection", those from other places within Chapter 1's Section 2 should be "Subsection 3", those from other places within Chapter 1 should be "Subsection 3 of Section 2", and those from the remaining places should be "Subsection 3 of Section 2 of Chapter 1".

---

Further, let's say I have theorems (via amsthm) interspersed throughout (they needn't occur only in subsections) numbered within section. I want the references to Theorem 2.1 (which occurs in Chapter 1's Section 2's Subsection 3) from within Chapter 1 to be called "Theorem 2.1", and from any other places to be called "Theorem 2.1 of Chapter 1".

Can this be achieved?

Answer 1

A proof of concept as you won't get warnings if the labels are wrong.

_{This style of references is very heavy and not a good service to your readers, in my opinion.}

\documentclass{book}
\NewProperty{chapter}{now}{0}{\arabic{chapter}}
\NewProperty{section}{now}{0}{\arabic{section}}
\NewProperty{subsection}{now}{0}{\arabic{subsection}}
\NewDocumentCommand{\chapterlabel}{m}{%
  \label{ch:#1}%
  \RecordProperties{ch@:#1}{chapter}%
}
\NewDocumentCommand{\sectionlabel}{m}{%
  \label{sec:#1}%
  \RecordProperties{sec@:#1}{chapter,section}%
}
\NewDocumentCommand{\subsectionlabel}{m}{%
  \label{subsec:#1}%
  \RecordProperties{subsec@:#1}{chapter,section,subsection}%
}
\ExplSyntaxOn
\NewDocumentCommand{\chapref}{m}
 {
  \str_if_eq:eeTF { \property_ref:nn { ch@:#1 } { chapter } } { \arabic{chapter} }
   {
    this~chapter
   }
   {
    chapter\nobreakspace\property_ref:nn { ch@:#1 } { chapter }
   }
 }
\NewDocumentCommand{\secref}{m}
 {
  \str_if_eq:eeTF { \property_ref:nn { sec@:#1 } { chapter } } { \arabic{chapter} }
   {% we're in the same chapter
    \str_if_eq:eeTF { \property_ref:nn { sec@:#1 } { section } } { \arabic{section} }
     {% we're in the same section
      this~section
     }
     {% different section, same chapter
      section\nobreakspace\property_ref:nn { sec@:#1 } { section }
     }
   }
   {% different chapter
    section\nobreakspace\property_ref:nn { sec@:#1 } { section }~
    of~chapter\nobreakspace\property_ref:nn { sec@:#1 } { chapter }
   }
 }
\NewDocumentCommand{\subsecref}{m}
 {
  \str_if_eq:eeTF { \property_ref:nn { subsec@:#1 } { chapter } } { \arabic{chapter} }
   {% we're in the same chapter
    \str_if_eq:eeTF { \property_ref:nn { subsec@:#1 } { section } } { \arabic{section} }
     {% we're in the same section
      \str_if_eq:eeTF { \property_ref:nn { subsec@:#1 } { subsection } } { \arabic{subsection} }
       {% we're in the same subsection
        this~subsection
       }
       {% different subsection, same section
        subsection\nobreakspace\property_ref:nn { subsec@:#1 } { subsection }
       }
     }
     {% different section, same chapter
      subsection\nobreakspace\property_ref:nn { subsec@:#1 } { subsection }~
      of~section\nobreakspace\property_ref:nn { subsec@:#1 } { section }
     }
   }
   {% different chapter
    subsection\nobreakspace\property_ref:nn { subsec@:#1 } { subsection }~
    of~section\nobreakspace\property_ref:nn { subsec@:#1 } { section }~
    of~chapter\nobreakspace\property_ref:nn { subsec@:#1 } { chapter }
   }
 }
\ExplSyntaxOff
\begin{document}
\chapter{Test}\chapterlabel{testchapter1}
\chapref{testchapter1} --- \chapref{testchapter2}
\section{Test}\sectionlabel{testsection1}
\subsection{Test}\subsectionlabel{testsubsection1}
\section{Second}\sectionlabel{testsection2}
A: \secref{testsection1}. B: \secref{testsection2}. C: \secref{testsection3}
\subsection{AAA}\subsectionlabel{testsubsection2}
A: \subsecref{testsubsection1}.
B: \subsecref{testsubsection2}.
C: \subsecref{testsubsection3}.
\chapter{Second}\chapterlabel{testchapter2}
\section{Again}\sectionlabel{testsection3}
\subsection{BBB}\subsectionlabel{testsubsection3}
\end{document}

We record more properties for a single \...label and so we're able to check them one by one.