\version "2.8.7"

#(define (compound-time-2m one two three four)
 (markup #:override '(baseline-skip . 2) #:number
  (#:line ((#:column (one two)) #:lower 1 "+" (#:column (three four))))))

staffOne = \context Staff = "1" {
  \time 3/4
  \override Staff.TimeSignature #'stencil = #ly:text-interface::print
  \override Staff.TimeSignature #'text = #(compound-time-2m "1" "2" "3" "4")
  a4 b g | f4 g2 |
}

staffTwo = \context Staff = "2" {
  \time 3/4
  \override Staff.TimeSignature #'stencil = #ly:text-interface::print
  \override Staff.TimeSignature #'text = #(compound-time-2m "1" "2" "3" "4")
  a2. | g2. |
}


theMusic = \relative c'' {
  \context StaffGroup <<
    \context Staff = "1" {
      \set Staff.fontSize = #-4
      \override Staff.StaffSymbol #'staff-space = #(magstep -4)
      \override Staff.VerticalAxisGroup #'minimum-Y-extent = #'(-2 . 3)
    }
    \staffOne
    \context Staff = "2" {
      \override Staff.VerticalAxisGroup #'minimum-Y-extent = #'(-2 . 3)
    }
    \staffTwo
  >>
}

\score {
    \theMusic
    \layout {}
}