JavaScript for Rank Order question limited to 3 option (columns)

This should work for you!
Qualtrics.SurveyEngine.addOnload(function()
{
/*Place your JavaScript here to run when the page loads*/
for(var col=3;col<=26;col++){

jQuery(".ChoiceStructure .Answers").find("th:eq("+col+")").css("visibility","collapse");

jQuery(".ChoiceStructure tbody tr").each(function(){

jQuery(this).find("td:eq("+col+")").css("visibility","collapse");

})
}
});

This way, it is just collapsing the columns instead of hiding/removing them completely.

Tnx Jacqueline, it seems to work indeed. However ... the column with item labels is cut off, creating a bit awkward presentation of the list. But I guess this can be fixed easily.
Another tweak that seems to work for now (don't ask why, but trial and error led me to this): changing the Validation Type to "Nono" and back to "Must rank between" again. It appears the system is stable now, also with the 'old' JavaScript.
I'm keeping my fingers crossed ... Qualtrics support is looking into the matter, as this kind of error should not happen (or at least we should know what causes the automatic transformation in some case, but not all). I have multiple questions with the same script and sometimes it changes, sometimes it stays as supposed to.

You must have been done with this by now, but here's a solution that works:
Demo here.
Qualtrics.SurveyEngine.addOnReady(function(){
rows = this.getChoiceContainer().querySelectorAll("tr");
for(i=0;i bl = rows[i].children;
for(j=4;j bl[j].hide();
}
}
});