Widget to display/edit custom attribute link?

[Walt]

We have a bunch of custom attribute links and are trying to create a user interface with an ftrack Action to enable display and editing.  Is there a widget we can use that natively allows editing of custom attribute links?  We can display the link using a text widget, but there doesn't appear to be native support for editing the link like we can through the custom attribute list of an object - searching by name, selecting a new link, clearing the link, etc.