Specify a regular expression to build groups of jobs that will be categorized in the view.

If you use parenthesis to specify a group, the name of the group will be the group match.
If you don't specify any matching group, the whole expression will be used to build the group name.

Examples:

• "a[0-9]+" The group match will be an 'a' followed by a number.
• "a([0-9]+) The group match will be a just a number.