[@robin-w Moderator 6 years, 7 months ago]

yes, just change the line

'parent_forum' => 'any',

to

'parent_forum' => '123456',

you can find a forums number by looking at the url whilst you are editing it

dashboard>forums>all forums>edit (the forum you want) and in the url bar you will see

http://www.mysite.com/wp-admin/post.php?post=28109&action=edit