I have a query

SELECT p.*, m.*,
  (SELECT COUNT(*) FROM newPhotoonAlert n WHERE n.userIDfor='$id' AND n.threadID=p.threadID and n.seen='0')  AS unReadCount 
    FROM posts p
    JOIN myMembers m ON m.id = p.user_id
    LEFT JOIN following f 
    ON (p.user_id = f.user_id AND f.follower_id='$id' 
    AND f.request='0' AND f.status='1')
    JOIN myMembers searcher ON searcher.id = '$id' 
    WHERE ((f.follower_id = searcher.id) OR m.id='$id')
    AND p.flagged <'5' 
    ORDER BY p.threadID DESC,p.positionID

It brings result as expected but I want to add Another CLAUSE to limit the results. Say a sample (minimal shown) set of data looks like this with the above query.

threadID   postID positionID  url
  564       1254     2         a.com
  564       1245     1         a1.com
  541       1215     3         b1.com 
  541       1212     2         b2.com 
  541       1210     1         b3.com 
  523       745      1         c1.com
  435       689      2         d2.com
  435       688      1         a4.com
  256       345      1         s3.com
  164       316      1         f1.com
  .
  .

I want to get ROWS corresponding to 2 DISTINCT threadIDs starting from MAX, but I want to include duplicates as well.

Something like

AND p.threadID IN (Select just Two of all threadIDs currently selected, but include duplicate rows)

So my result should be

threadID   postID positionID  url
  564       1254     2         a.com
  564       1245     1         a1.com
  541       1215     3         b1.com 
  541       1212     2         b2.com 
  541       1210     1         b3.com