Placement of new Context

[Robert Schmaus]

Dear Lilyponders,

I've defined a new context

\layout{

  \context{

    \type "Engraver_group"
    \name "RhythmicLine"
    \alias "Staff"

    ....

  }

  \context { \Score \accepts "RhythmicLine" }

}

which works fine so far except that it always shows up at the bottom of
the system, no matter how I arrange the individual "\new Staff" etc.
within the StaffGroup. I can't seem to find the proper
command/setting/override that tells the context: your place within the
system is wherever you're placed within the StaffGroup.

Btw: I found a way to do it by naming staffs and then setting
\with { alignAboveContext = #"main" } for this Staff but that's not what
I mean ...

Does anyone know how to?
Cheers,
Robert