The requirement is to use a filter which will allow it to ignore matching devices that meet given criteria, while showing other devices that do match the filter.
For example the filter would match all items that begin with the letters 'an', but would filter out select items that start with 'an'.
Is using a “not equal” parameter possible?
Al supported Performance Management releases
The Filter Regex functionality for View and Inventory filtering fields using a 'not' match along with a match would be an Enhancement Request.
Enhancement Requests can be submitted via the Ideation page on the Broadcom Community site found here.
On possible workaround might be to set up a Group that is set against the View to provide what is sought. If the View being filtered is constrained by a Group via the Context settings, such as a View on a Dashboard, you could create a Group with regex rules and manually filtered out items. Then you could select that Group and get the functionality being sought.
Search and Filter in Performance Management documentation.