DigitalVolcano Software Support

How to mark files within same parent folder, but with the short folder path?

For example:
X:\Photos\Sub folder-abc\
X:\Photos\Sub folder\Sub Sub folder\Sub Sub..etc.

I would like
1. mark files in the 1st folder (shortest folder path)
2. always keep one file in each folder (for safety sake)

I -would- say:
under 'Mark by Group'
select
[Shortest folder path names in each group]
and
[Drive] [Start with] X:\Photos
or:
[Folder] [Start with] X:\Photos


However, this is also marking folders on other drives within the same duplicate listing, i.e. F:\Photos


or Mark by Location
X:\
but I can not select shortest folder path there.

Any suggestions?

Thanks!