I'm trying to find out how to share a subsite on Office 365, but I'm not able to figure it out. The idea is to have a site collection with a top level site "Projects". Then I will have subsites for different projects, where I want to share only that subsite with a particular external user.
But everytime I try to do this, the external user gets access to the parent site as well, which is not ok. And I don't mean that they should only have viewing privileges to the parent site, they shouldn't be able to access it at all.
I tried using unique permissions on the subsite, but that didn't help either. I'm not very familiar with groups yet, I fiddled with it as well as I could, but couldn't figure out any solution. So if it has to do with groups to achieve this, I would really appreciate an answer explained as plainly as possible...
I'm sure there must be a way to achieve this, it seems to be one of the common uses for Sharepoint that's often touted, but I haven't seen an explanation of how to do it.
Any help would be greatly appreciated!