I have a blog with two categories of posts that I don't want 'mixing' with the rest of the posts for purposes of the single post navigation. I've been able to modify the next/previous for all the other posts but I'm trying to modify for these two categories.
Using the parameters of next_post_link I can set in_same_term to true. The trouble is many of these posts have multiple categories assigned. What I'm trying to do is restrict the previous / next links to only the one cateogry. So, in this case the category I'm trying to stay in is ID 152. If the current post is in 152, 12, 19 I want the next and previous link to be to a post in category 152, not 12 or 19. Limiting the term (5th parameter) to 152 didn't work. Any ideas?