How can I display/filter all files which are tops of stacks?

[ubacher]

I could not find a way to just show all (files which are) the tops of stacks.

[Mario]

Which kind of stacks?
I recommend using the File Properties Filter.

[ubacher]

I am concerned with manually created stacks.
The File Properties filter only shows me files below the top ("stacked")
or all stacks - including the version stacks.

I found a way using a data driven category filtering on {File.Stack.IsTop}.
This gives me what I am looking for.
Having Show Stack tops part of the File Properties Filter may be desirable.

[Mario]

Properties filter.
Hide stacked files.
Invert.

Does that not work?

[Darius1968]

Having both - File Properties>Hide stacked files, File Properties>Show files which are part of a stack - checked works. 

[ubacher]

Neither Mario's suggestion nor that from Darius gives me all the files which have
{File.Stack.IsTop} set i.e the top of stacks excluding version stacks.

[Mario]

Not every filter can do everything, I'm afraid.

Hide stacked files shows only the tops.
Inverting this filter shows only the files in stacks, not the tops.

Hide versions hides version files, showing only the masters (top).
Hide masters hides the masters, keeping only the versions.

I think this covers most typical use cases.