newbibmacro*{cite:seen:related}{%
 {xifinlistcs{thefield{crossref}}{blx@bsee@thec@refsection}
   {}
   {listcsxadd{blx@bsee@thec@refsection}{thefield{crossref}}}}}

newcommand{ifrelatedunseen}[2]{%
  xifinlistcs{thefield{crossref}}{blx@bsee@thec@refsection}
   {#2}
   {#1}}

renewbibmacro*{cite}{%
  usebibmacro{cite:citepages}%
  globaltogglefalse{cbx:fullcite}%
  globaltogglefalse{cbx:loccit}%
  bibhypertarget{citethevalue{instcount}}{%
    ifciteseen
      {iffieldundef{shorthand}
         {ifciteibid
            {usebibmacro{cite:ibid}}
            {ifthenelse{ifciteidemANDNOTboolean{cbx:noidem}}
         {usebibmacro{cite:idem}}
               {usebibmacro{cite:name}}%
             usebibmacro{cite:title}}%
          usebibmacro{cite:save}}
         {usebibmacro{cite:shorthand}}}
      {ifboolexpr {
         test {iffieldundef{crossref}}
         or not ( test {ifentrytype{inbook}}
               or test {ifentrytype{incollection}} ) }
       {usebibmacro{cite:full}%
        usebibmacro{cite:save}}
       {ifrelatedunseen
        {usebibmacro{cite:seen:related}%
         usebibmacro{cite:full}%
         usebibmacro{cite:save}}
        {usebibmacro{related:info}}}}}}

newbibmacro*{related:info}{%
  usedriver{}{inbook:rel}}

DeclareBibliographyDriver{inbook:rel}{%
  usebibmacro{bibindex}%
  usebibmacro{begentry}%
  usebibmacro{author/translator+others}%
  setunit{labelnamepunct}newblock
  usebibmacro{title}%
  newunit
  printlist{language}%
  newunitnewblock
  usebibmacro{byauthor}%
  newunitnewblock
  usebibmacro{in:}%
  usebibmacro{maintitle+booktitle}%
  newunit%
  bibstring{opcit}%
  newunitnewblock
  usebibmacro{chapter+pages}%
  newunitnewblock
  setunit{bibpagerefpunct}newblock
  usebibmacro{pageref}%
  newunitnewblock
  iftoggle{bbx:related}
    {usebibmacro{related:init}%
     usebibmacro{related}}
    {}%
  usebibmacro{finentry}}