How to exclude folders from VS Code ObjectScript search

I have a VS Code workspace using server-side editing with separate folders for different namespaces on the instance:

{
	"folders": [
		{
			"name": "SYS",
			"uri": "isfs://server:%SYS/"
		},
		{
			"name": "cls",
			"uri": "isfs://server:USER/?filter=*.cls"
		}
	]
}

The VS Code search works well to find symbols in ObjectScript files, but it searches across all folders. Is there a way to include or exclude certain folders from the search? I've tried adding some patterns to the "files to exclude" dialog, but none of these seem to work: SYS/**, /SYS/**, %.*, \%.*