Apply access restriction to several epics or several tickets

[Deleted user]

Hi, 

We are using a next-gen software project and we have created a role dedicated to external collaborators. Our problem today is that in order to apply the restriction rule, we have to change the restrictions (by selecting the roles) ticket by ticket. I'd like to know if there is a more efficient way to make tickets of certain epics visible/accessible to a certain role(external user)?

Thanks in advance!

Ying