No - works fine here (and for most everyone else).  If you want to 
create a folder in /root/existingfolder, then you need to click on the 
checkbox next to existing folder, select "create folder", and enter 
"newfolder" in the box.

When trying to create subfolders, the only way this can be done is 
from the root and you have to specify a complete path to the intended 
destination i.e. /root/existingfolder/newfolder