Different pages navigation on sidebar

Hey There,

I am trying to figure out the best way get only select pages in my left sidebar.

For example:

If someone is on the page “Buying Land” there are about 8 sub pages under it. I am using the plugins flexipages and collapsing pages so under the parent page and subpages of “Buying Land” there are other parent pages on the sidebar. What I would like to do is, when someone is on a page I would like to only display pages on the left sidebar that are associated with the Parent Page, not any of the other pages. I would like to get rid of the other pages that aren’t relavent to the page the reader is on.

Further example:
the reader is on Buying Land

Buying Land (parent page)
-subpage
-subpage
-subpage
-subpage
-subpage
-subpage

Build It (parent page) (don’t want these pages displayed EXCEPT when a reader is on these pages)
-subpage
-subpage
-subpage
-subpage
-subpage

Design (parent page) (don’t want there pages to be displayed EXCEPT when a reader is on these pages)
-subpage
-subpage
-subpage
-subpage
-subpage

etc…

Can this be done? Thanks for the help!