WinSCP auto Synchronization files of local subfolders directly into root’s remote

I couldn’t find in the Auto Synchronization of folders the option to copy files from sub-folder without copying the full folder structure into the root of remote location.

Is something I’m missing or is there a way that I can achieve this with some turnaround at least?

example

local/folder1/file1.wav
local/folder2/file2.wav
local/folder2/file3.wav
local/folder2/file4.wav
local/folder3/file5.wav

into

root/file1.wav
root/file2.wav
root/file3.wav
root/file4.wav
root/file5.wav