Basic matching (without regular expressions)

Private

This is the default folder selection type.
✅Private
✅Private/Example
❌Inbox/Private
❌Private Stuff
Private/.

Exclude subfolders by appending /.
✅Private
❌Private/Example
❌Inbox/Private
❌Private Stuff

 Regular Expressions

Prefixing with || indicates that you are doing a regex match against the entire folder tree, including parent folders.

The folder name starts from the mailbox root, with folders separated using /.

Regex is a case-sensitive substring match by default.

||Example

Matches "Example" (case sensitive) anywhere in the folder structure.
✅Example
✅This is an Example Folder
✅Inbox/Example
✅Inbox/My Example Folder
❌example in lowercase
|i|Example

|i| prefix indicates a case insensitive match.
✅Example in uppercase
✅example in lowercase
|i|(^|/)Example(/|$)

^ matches the beginning of a string, and $ matches the end. (^|/) matches either the start of the folder path or a folder separator, and (/|$) matches either a folder separator or the end of the path.

This selects the exact folder name "Example" along with any of its subfolders, but does not select folders such as MyExample or ExampleStuff.
✅Example
✅Inbox/Example
✅Inbox/Example/Stuff
❌MyExample
❌ExampleStuff
|i|(^|/)Example$

A slight variation on the above, this selects the same "Example" folders but does not select their subfolders. It selects Example and Inbox/Example, but not Inbox/Example/Stuff.
✅Example
✅Inbox/Example
❌Inbox/Example/Stuff
❌MyExample

All of these can be entered (or copy/pasted) into the Include or select list windows as appropriate. To test interactively, create a temporary Single Mailbox profile which archives just a single mailbox containing appropriate test folders. This exposes the "Show Effective Folders" button. Once you have a configuration that works the way you want, copy/paste the results into your normal Multiple Mailbox profile.