I was hoping it would work with aliases, since they are easier to create in the Finder. All is well, though, if instead of aliases we use symlinks.
Here is one way to create symlinks from folders A, B, C inside another folder D:
1) open Terminal
2) type “cd “ without the quotes but with a trailing space; do NOT press enter
3) Drag folder D over the Terminal window (it expand its full path into the command line)
4) press enter to execute the command
5) type “ln -s “ again with a trailing space and no enter
6) drag folder A iver Terminal
7) type a period, and then press enter
(the command line will look line this:
ln -s /Users/path/to/folderA .
)
repeat steps 5)-7) for each folder you want to make a symlink for