iterating the token stream backwards by scope

iterating backwards by scope

i have a contenxt is which to do "intellisense" i need to look backwards.. here is an example

get-command "blablabla" -sth


when i type the - before something, i will lookback in the stream for an CmdLetToken (which get-commands is matching based on the XML definition).. and then use that to find out the parameters i should show..
in a simple situation this is easy (i just readreverse until i hit a cmdlet token or a lineterminatingtoken. However something liek this is a bit harder

get-command $(other-cmdlet "balbla ) -sth

or

get-command { other-cmdlet
"something else" } -sth

IS THERE a way i can read back in the same "scope" level that i am?

Karl