I'm not sure I understand the question. You haven't made your look-behind or look-ahead assertions optional, so both should
already be required. Your expression should already be
logically correct. But I'm not certain whether you're looking for instances where the bullet IS or ISN'T enclosed with p tags.
IS
Code:
(?<=<p class="calibre1">)•(?=</p>)
ISN'T
Code:
(?<!<p class="calibre1">)•(?!</p>)