Ditto command and wildcard on Catalina?
You need to use a for loop for this (works in both zsh and bash):
for target in &quot;dir1&quot; &quot;dir2&quot; &quot;dir3&quot;; do
    ditto -- &quot;myfile.css&quot; &quot;testingdir/$target&quot;
done

If the target directories are actually called dir1 etc you can use wildcard expansion
for target in dir[1-3]; do
    ditto -- &quot;myfile.css&quot; &quot;testingdir/$target&quot;
done