Dropdown filter element from canvas workpad does not appear when shared on a external website

[thimothe-das]

Describe the feature:
When you display your canvas workpad on an external website with the kibana feature : "share on a website", dropdown filter element are not displayed.
Is it something you plan on adding in the feature ? If you do, do you know when such a feature will be added ?
Describe a specific use case for the feature:
Dropdown filter element allow to easily filter a graph or any stats by date or other specific metrics. It is a great tool for non developer who which to analyze their datat efficiently

[elasticmachine]

Pinging @elastic/kibana-canvas (Team:Canvas)

[clintandrewhall]

Good evening Thimothe! The Shareable Runtime expressly excludes all filtering controls. A Shared Workpad is a snapshot of data-- as it is a flat JSON file and not connected to any datasources, like ES-- so filtering controls would have no effect on the workpad:

https://github.com/elastic/kibana/blob/master/x-pack/legacy/plugins/canvas/shareable_runtime/README.md#supported-expressions

We're working diligently on creating a Shared Workpad implementation that is connected to datasources, but it is a few releases away. As you can imagine, there are a lot of security questions to answer about a publicly-shared workpad that can access real, live data ad-hoc. You can follow our progress and weigh in here: #48584