Backup all except with sub-servers

I have multiple servers:

• s1
• s2
  • s2.sub1
  • s2.sub2
• s3
• s4

I would like split backups to 2 parts:

1. Only s2+subservers
2. All except s2+subservers.

For first backup: mark "Only selected ..", mark s2 and checkbox "Include sub-servers of those selected" Running this backup runs as expected and backups s2, s2.sub1, s2.sub2.

For second backup: mark "All except ..", mark s2 and checkbox "Include sub-servers of those selected". I would expect it should backup s1, s3, s4. However it also backups s2.sub1, s2.sub2.

I think checkbox "Include sub-servers of those selected" should work as "Exclude sub-servers of those selected" when "All except .." is chosen.

To workaround, now I need to select all s2, s2.sub1, s2.sub2 and update list everytime when I add subservers to s2.

I also suggest to display server list as tree like on the left, so subservers are better visible.