Adding widgets to centre of buddypress fun

Hi

How do I add content (or widgets) to the centre of my buddypress fun theme?

Please see attached image for where I mean. I'm hoping this will also fix the problem I have here; https://premium.wpmudev.org/forums/topic/why-dont-categories-display-on-classifieds-page

I can't seem to get anything to this part of the site on any page except for blog posts.

Am I able to add widgets to this area on different pages/sections of my site, to allow me to have a summary of classifeds categories at the top of my classifieds page?

Also, when I add any widgets to the left, centre or right column in my theme, nothing changes on any pages. What are these supposed to be for? Only blog sidebar, buddypress right and bbpress sidebar actually add widgets.

Thanks.