multiQuote = \relative c'' {
  <<
    { \voiceOne c4 d e f } \\
    { \voiceTwo a,4 b c e }
  >>
}

singleQuote = \relative c'' {
  bis4 c d e |
}

\relative c' {
  c1 |
  d1 |
  \new CueVoice { \multiQuote }
  a1 |
  \new CueVoice { \singleQuote }
}

Quotea = \relative c'' {
  \voiceOne c4 d e f
}

Quoteb = \relative c'' {
  \voiceTwo a4 b c e
}

singleQuote = \relative c'' {
  bis4 c d e |
}

\relative c' {
  c1 |
  d1 |
  <<
    \new CueVoice { \Quotea }
    \new CueVoice { \Quoteb }
    \override MultiMeasureRest.staff-position = #-4 R1
  >>
  a1 |
  \new CueVoice { \singleQuote }
}