Team Member option to view bio description

one way could be the very old way to set something in this html :

<details>
  <summary>Details</summary>
  Click here to add your own text 
</details>

you can add that to the team member description field – there are warnings about using tags – but it will work!

Or you do not enter the description to the team member element but in a separate text-block under the team member element.
On newer enfold versions there are options to fold/unfold text-block element just below the content input text area.

see both alternatives here:
https://webers-testseite.de/team-member/

OK
Of course you can replace the details text. (not that one in the tag – but surrounded by the details tag)

Yes – i belong to the Text inside <summary>XYZ</summary>

by the way if you like to have only one details open at the same time:

function only_one_details_open(){
?>
<script type="text/javascript">
(function($){
    $('details').on('click', function(){
        $('details').not(this).removeAttr("open");  
    });
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'only_one_details_open');