membersOf Dynamic group based on other dynamic groups

PlafoCL 

If you shift the focus to what you're trying to achieve rather than how you've proposed on doing so, there are some options you can explore.

Below is a dummy example related to your Dynamic Group E scenario.

This examples does indeed produce the union (of user objects though, not groups) of two other dynamic groups through using the memberOf attribute on the user object rather than memebrOf on the group objects.

The initial output is from the dynamic group (i.e. analogous to your Dynamic Group E) that holds the union of two other dynamic groups. This also show the rule which has the "and" join highlighted for clarity.

The second round of output is purely confirmation that the two groups being compared are indeed dynamic.

The final output is simply a count of how many members the first group contains as a result of the rule processing.

Using this slightly different approach, you probably can satisfy the four deliverables you've outlined.

Cheers,

Lain