How to test is_protected_by_s2member() output in shortcode conditionals

I need to build a conditional logic based on the restriction level of the current page.

I would like to test, in a shortcode conditional statement [s2If], the value of the field “s2member_level_req” returned by the API function is_protected_by_s2member(),

I’m able to do it using the following php code:

<?php if (is_protected_by_s2member()["s2member_level_req"] == 4) echo 'OK 4'; ?>

but I cannot figure out how to get a shortcode conditional equivalent of the php snippet, e.g. something similar to:

[s2If (is_protected_by_s2member()[“s2member_level_req”] == 4]
Ok 4

Is that possible?
Thank you in advance.