I copied the template from the demo, but didn't manage it to work.
The template seems to only be loaded if already on cache, and when loaded I got the error
Error: [$parse:syntax] Syntax Error: Token '{' is not a valid identifier at column 6 of the expression [node.{{options.nodeChildren}} | filter:filterExpression:filterComparator {{options.orderBy}}] starting at [{{options.nodeChildren}} | filter:filterExpression:filterComparator {{options.orderBy}}].

Is the example outdated? Any clue on how to make it work?