\version "2.18.2"

\score {
  \relative c' {
    \new StaffGroup <<
      \new Staff {
        \global
        e1 | e
        \once \override Staff.BarLine.allow-span-bar = ##t
        e1 | e | e
      }
      \new Staff {
        \global
        c1 | c | c
        \once \override Staff.BarLine.allow-span-bar = ##t
        c1 | c
      }
      \new Staff {
        a1 | a | a | a | a
      }
    >>
  }

  \layout {
    \context {
      \Staff
      \override Staff.BarLine.allow-span-bar = ##f
    }
  }

}