(Simple enough) Change from php code in plugin to template code

[noppid]

Looks fine. It should work with or without the grouping Lynne suggests. Making them explicit can be faster though.

<if condition="($thread['postuserid'] == $this->registry->userinfo['userid']) OR ($this->registry->userinfo['permissions']['answers_forum_perms'] & $this->registry->bf_ugp_answers_forum_perms['canselect_others_answers'])">
</if>

Do not change the & to AND. It is a bitwise arithmetic operation. AND is a logical operator.