Unfortunately this didn't work for me.
If a directory contains several subdirectories not all of which shall be checked out into the working copy,
I see the following log (only beginning)
Command: Checkout from
https://myhost.com/repos/acs64/septa, revision HEAD, Unknown depth, Externals included
Updating: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir
Updated: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir
Completed: At revision: 1122
Command: Sparse update CCU, depth 'Only this item'
Updating: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU
Added: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU
Completed: At revision: 1122
Command: Sparse update CCU/branches, depth 'Fully recursive'
Updating: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU\branches
Added: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU\branches
Completed: At revision: 1122
Command: Sparse update CCU/trunk, depth 'Fully recursive'
Updating: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU\trunk
Added: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU\trunk
Added: D:\PRJ\2017-11-29_svn_ext_chooseitems\septa-without-septadir\CCU\trunk\CPU
[...]
Although the first line lists "externals included", it doesn't seem to include externals for this directory!
but the external directory reference in this node does not seem to get processed.
(Externals that are deeper in the tree are processed just fine, as far as I can see.)
The repo browser shows and handles externals almost like directories.
Could the "Choose items ..." dialog be made behave like the repo browser, and would the underlying
checkout / update engine be able to select externals to be included / not to be included?
With best regards
Hartmut