We need to enable Teams External access separation for a particular domain

[ayenco]

In my organization we have two domains (domain1 and domain2) and we allowed all users to communicate with team1 and team2 respectively in both domains, then we need to provide another domain (domain3) and we need to set permission only for some set of users in domains 1 and domain 2 to have access to domain3. That no one should have access to the domain3 unless we allow users in domain1 and domain2 to have access to the third domain. Any help on how to achieve this?

@Eric Marsi  

@ChristianJBergstrom 

@jjrice2233 

@Christopher Hoard 

@Allen Xu_MSFT 

@Satish2805 

@Steven Collier 

@Ashok_Boinpally 

@paul keijzers 

@Bryan Nyce 

@adam deltinger  

@Chris Webb 

@paul1502 

@Graham Walsh 

@JimmyYang-MSFT 

Zhengqi Lou-MSFT 

Vasil Michev 

Nate Loback 

Yuki Sun-MSFT 

@Juan Carlos González Martín 

@Satyendra Sharma 

[#2]

If your use case doesn't involve communication across tenants then you can have a look at Information barriers https://docs.microsoft.com/en-us/microsoftteams/information-barriers-in-teams

I would also encourage you to look at the new feature in preview "cross-tenant access settings"
https://portal.azure.com/#blade/Microsoft_AAD_IAM/CompanyRelationshipsMenuBlade/CrossTenantAccessSet...

And also highlight that the "shared channels" feature is on it's way. Great video here.
https://myignite.microsoft.com/sessions/cfcdfdfa-7401-414d-ab61-4e834281e7ae with a Public Preview in a couple of months.

Perhaps any of these will solve puzzle you're trying to figure out.

[#3]

@ayenco Please do not tag people to get attention, anyone here might offer you an insight into your questions.

Assuming that by 'domain' you are referring to users all within the same tenant then the only control to limit communication between groups of users is the E5 feature called Information Barriers. This would block messaging, being in the same team, joining meeting etc. and its built for regulated industries like banking.