Header that partially scrolls, partially freezes?

If it’s not EditorX then:

  1. if you need it on both desktop and mobile view, you’ll have to create the element using custom element (html, css).

  2. If it’s for desk top only, I think you can create 2 strips with the header contents. 1 of them will be scrolled with the page and the other one pinned to screen. Add anchors to the page and expand-collapse each of the the boxes based on the scroll position.