Right. The bot see the text an the user see the button. That are different things.
So I ask a Google engineer about the problem. Can this hurt my site?
And the and the answer was Google like: YES and NO
If the major text content of a page "hidden" in this way this not good for your site.
Be Careful.
Are you running it, user-friendly than it is ok.
I think everyone should assess the risk for themselves.
<xen:if is="!{xen:helper ismemberof, 1, 2, 3, 4}">
Do not show this
</xen:if>
Then, no. XF conditional statements are compiled as PHP code so the effects of that code are server side meaning if something is hidden inside a conditional such as the one above, then Google can't see any trace of that happening at all.