Depending on how are the things organized on your server you might have issues with permissions, but withing one single account it's possible to symlink public_html so it would share its content between domains:
/home/abc/domains/abc.com/public_html
/home/abc/domains/abcd.com/public_html --symlink-to--> /home/abc/domains/abc.com/public_html
/home/abc/domains/abcdef.com/public_html --symlink-to--> /home/abc/domains/abc.com/public_html
To share public_html between different users more actions are required.
sort of seems related to this
http://www.directadmin.com/forum/showthread.php?t=44098
Yes, I hope that I can have a way like cpanel did. It's very easy from Control Panel.
Thanks.
If you want to add alias (it's Domain Pointers at User Level), there is already ability to do it with Directadmin:
http://site-helper.com/misc.html#pointers
To point different domains to one public_html you can create aliases. My first solution was intended to be used if you want to have independent email boxes for every aliased domain.