hide and show on headers and icons (+/-)

hi, i want to hide the hide the text and the icon(+/-) in the header field on click of a button, is that possible?
i used hide and its variants, i could not come through.
for now i am able to assign a null value to groupText but the icon still remains.
in the below snippet, when i Group “Great Grand Father” i want “Grand Father” and “Father” to show nothing(Not the icon too).
like wise, when i click on “Grand Father”, the “Great Grand Father” and “Father” row should become empty.
also, the same with the “Father”, “Great Grand Father” and “Grand Father” should be empty.

and after un grouping, everything hid should shown.

http://webix.com/snippet/de851a12

There is no ready to use solution, and I don’t see the easy way to add one without full rewriting of custom header elements.

Current implementation of collapsible columns was created for one-level collapsing. While multi-level functionality, as in your snippet, can work, it is not expected use-case and doesn’t have a good API and UI support.

ok, for now lets forget about collapse.

Can we hide the text and icon? by a button click.