Add some screenshots to describe your question, we can probably tell you directly what you need to do.
Possibly you need to do this: “all the data available" comes from the elements that are on the page in Mendix Studio (and Pro). Just delete them to make sure they do no longer get displayed.
You build a page which shows all attributes from the entity (I guess you already have it). You pass the magical parameter to the page which tells what attribute you want to see. Then for each attribute from the entity you configure ‘Visibility’ property to depend on expression. You build expression depending on the magical parameter to make the widget visible.