Hi Eva:

Yes, you can use either site- or project-wide security groups for users, then assign roles to the group in whatever context you need. Documentation is here:

• Security Groups

We can also move this question to your custom support portal linked from here for detailed followup about your specific needs.

--Molly

Hi Molly,
Thanks for your quick answer, we'll take a look at the documentation you propose.
About moving this question, yes, if you know how to do this, please move it to our support portal (in fact that was my intention when I created it...).
All the best,
Eva