Persistent Multi-select of clients in access mode

This morning I found I needed to run a command on several clients in access mode (I need to do this every few weeks.).  My clients are filtered into groups like so:

Company1

       DepartmentA

       DepartmentB

       DepartmentETC......

Company2

       DepartmentA

       DepartmentB

       DepartmentETC......

I needed to make changes to clients in several departments.  I selected the Company heading so I could see all the clients, without being filtered into departments.

The list long, so I used the the search at the top of the list to narrow my search in order to quickly locate the next client to select. After selecting each client ( locating them via the search ) I found that only the last client was selected. In fact every time I changed my view, the selections would go away.

I would to be able to have selection persist through new searches using the search filter at the top.

I have confirmed this is not an issue with the way I filter my clients in to groups, because it behaves the same when I am seeing all clients across all customers.

In case it is my filter, here it is for you to see:

CustomProperty1, IIF (CustomProperty2 <> '', CustomProperty2 + ' ' + IIF(GuestOperatingSystemName LIKE '*Server*', '!Servers', IIF (GuestOperatingSystemName LIKE '*Windows*', 'PCs', 'Other')), IIF(GuestOperatingSystemName LIKE '*Server*', '!Servers', IIF (GuestOperatingSystemName LIKE '*Windows*', 'PCs', 'Other')))