Answer might be no. I can't seem to get it to work, either for the _default folder or a new folder. What I tried:
[file-manager::scholarships-profile-folder-_default]
name = Presentation (live2)
path = $SEARCH_HOME/conf/scholarships-web/_default2
rules = preview-display-rules
set =
Filesystem:
$ ls $SEARCH_HOME/conf/scholarships-web/_default2
blending.cfg
Admin UI:
scholarships-web / Presentation (live2)
No files to display.