Share extension only with specific URL

Question

Is there a way to filter Share extension to show only when, for example, the URL domain is a specific one?

For example, I want to show my app extension only when the user is sharing a google link:

http://www.google.com/?someQuery

If I'm filtering to get URLs, a code like below would be sufficient:

SUBQUERY (
    extensionItems,
    $extensionItem,
    SUBQUERY (
        $extensionItem.attachments,
        $attachment,
        ANY $attachment.registeredTypeIdentifiers UTI-CONFORMS-TO "public.url"
    ).@count == $extensionItem.attachments.@count
).@count == 1

In this case the predicate access the $attachment's registeredTypeIdentifiers property and evaluate it. I want to be able to match a REGEX against the value inside the $attachment, something like this:

SUBQUERY (
    extensionItems,
    $extensionItem,
    SUBQUERY (
        $extensionItem.attachments,
        $attachment,
        ANY $attachment.registeredTypeIdentifiers UTI-CONFORMS-TO "public.url" AND
        ANY $attachment.value MATCHES "^http\:\/\/www\.google\.com\/"
    ).@count == $extensionItem.attachments.@count
).@count == 1

... so my extension would be invisible when my application don't support the URL shared by the host app.

PS: Note that the URL domain used is only an example. The real one, of course, have a meaning to be used like this.