Steps to reproduce:

1. Create user group with host permissions
   1. hostGroup1 - Read-write permission
   2. hostGroup2 - Read permission
      
2. Create user with admin role and assign user this group
3. Create maintenance and  set it for 2 host groups
4. Login as user and go to  Data collection > Maintenance

Result:
User does not see this maintenance.

User see maintenance icon next to hosts (for Read-write and Read permission).

Please see screencast

NOTE:
In addition, same behaviour if user has Read write permission for one host group and Deny permission for 2nd host group, user does not see maintenance period.

And user does not see maintenance icon for host.

Expected:
User has Read-write and Read permission for mentioned host groups. He should see maintenance, but not be able to change it.