Office 365 Group as team

[vffdd]

I tried adding an office 365 security group as a member of a team it shows up as an option  when I search for user but when I click on Add it says "One member already exists in this team"  and it also doesn't give me the drop down to choose "Member" like it does for adding an individual.

The permissions on the sharepoint belonging to this team are controlled by that Office 365 group (membmers of the group have specific permissions on the site)  I don't want the Admin to have to control access in 2 places Sharepoint and Teams.. So I wanted them to add people to the Office 365 group that would give them the relevant access on Sharepoint and also on teams, works for Sharepoint but can't get it working on Teams?  Is it not possible ? It says you can add a security group?

[#2 · Accepted solution]

You cannot "nest" groups within M365 Groups. Some UI bits might "allow" this to happen, but in reality they expand the (current) membership of the group and add each user individually.

[#3]

That's fine I don't mind each user being added as an individual but I just don't want to have to add them "individually" !! Is there no way around that?  So why does it say 

If you can only add individuals?

[#4]

Actually I think I know what the issue is ! And your comment about expanding the current membership gave me a hint ! There actually wasn't anyone in the group that I picked !!
So I tried another one and it worked... but does that mean that if I add someone afterwards to the office 365 group they won't be added to the teams automatically?

[#5]

They won't, it's a one-time operation.