We currently only support inclusive filters in Advanced Queries, meaning all of our available filter parameters will only accept values to filter your report by, and not to exclude from your report.
Filtering on wildcard values is also not supported at this time. For example, you can filter your query on a specific page path, but we do not support at this time filtering the query for "path contains = /xyz/".
If this functionality is important for your team, we'd like to know! Email us the nitty gritty details at firstname.lastname@example.org and we'll make sure your feedback is heard.