I need to create a two-layered PopUp for ArcGIS Online and Webappbuilder. When initially selecting the feature in the map only basic information should be shown:

When clicking hide/show more information the content should extend:

I was intending to use HTML in combination with a simple JavaScript command, but it seems that this is not possible.
What is the ideal workaround for this?
PS: alternatively - instead of clicking hide/show more information - would it be possible to extend the content when maximizing the popup window?