Hello Mazin,
Assuming that the HR Manager can see attendance for the current branch, The Manager would have a role like Manager assigned to their profile.
go to the HR Managers user profile. click on the Manager security role, Click Assign organizations, select the Organization they are requesting the access for.
You might have a custom role that gives the user access to attendance. If that's the case, find out which role gives the HR manager access and just assign the requested organization to that role.
Depending on your organizations policy, make sure proper paper work has been filled out approving the access requested.
Hope this helps!