You can share folders as you normally would within Dropbox. You may find this page useful:
https://www.dropbox.com/en/help/19
What you can also do with your folders in Dropbox, is name them. So you could have:
614100001_My_Company_Ltd 614100002_Another_Company_Ltd
It can help keep things a bit more organised. There’s a bit on this in our own guide, here