subdirectory patterns in .jazzignore?

Say I have a tree with, for example's sake, a subtree like:

a
|__b1
| |__ c1
| |__ c2
|__b2
|__c3
|__c4

and I wish to ignore c2 and c4 from SCM.

Is there a .jazzignore I can add under 'a' to make this happen?

It can't simply refer to (unqualified) 'c2' or 'c4' since those may appear elsewhere in the tree (not shown) but I only want to ignore a/b1/c2, a/b2/c4.

I realize I can use .jazzignore under b1 and b2 simply enough to make this happen... however, in my case there is some value having all the ignored folders in one place (under 'a') for simple reference...rather than having to find them nested at all different subdir levels.

However, things like this don't seem to help any in a's .jazzignore:

core.ignore.recursive = {b1/c2}

Thanks