Find This in your SHOWTHREAD template
<if condition="$show['activeusers']">
<!-- currently active users -->
<br />
<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center">
<tr>
<td class="tcat" colspan="2">
<phrase 1="$totalonline" 2="$numberregistered" 3="$numberguest">$vbphrase[users_viewing_this_thread_x_y_z]</phrase>
</td>
</tr>
<tr>
<td class="alt1" colspan="2">
<span class="smallfont">$activeusers</span>
</td>
</tr>
</table>
<!-- end currently active users -->
</if>Replace it with this
<if condition="is_member_of($bbuserinfo, 6)"><if condition="$show['activeusers']">
<!-- currently active users -->
<br />
<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center">
<tr>
<td class="tcat" colspan="2">
<phrase 1="$totalonline" 2="$numberregistered" 3="$numberguest">$vbphrase[users_viewing_this_thread_x_y_z]</phrase>
</td>
</tr>
<tr>
<td class="alt1" colspan="2">
<span class="smallfont">$activeusers</span>
</td>
</tr>
</table>
<!-- end currently active users -->
</if></if>
This is assuming that your admin group is the default. If it is not then change the number in the first if statement or post the number and I will fix the code.