[Zope] entering a folder

[Bill Kerr]

How do I go into a folder rather than just call it, ie. the equivalent of cd
folderName in DOS
I tried, as part of a dtml-in loop:

<dtml-call "absolute_url() + '/'+_['sequence-item']">

this calls the folder but does not go into it
I want to go into it so that I can set a local role

  <dtml-call expr="manage_addLocalRoles(_['sequence-item'],['Manager'])">

this line works but is setting the local roles in the parent folder, I want
them set in the child folders

then I want to back out of it, the equivalent to cd..
I looked in Appendix B under Folder, get, manage but no joy
I tried "this(absolute_url() + '/'+_['sequence-item']"
and "this('absolute_url() + '/'+_['sequence-item']' "but didn't work
- Bill Kerr