Using the Page Editor, we have access to so many amazing widgets. I assumed that when placed on a subforum page, they would only appear there, but they actually appear in all subforums.

Is there a way to achieve this, possibly with the custom css section of the widget?

If not for all the widgets, what about at least just inserting an image on a specific section?

Thanks.

You would need custom code for this. Whether or not you can use custom CSS to hide it or not is going to largely depend on what you wish to hide and from where (you would be best to post in the customisations forum for that). Widgets are attached to a page 'type' rather than a specific page. So if you add one to a topic page, it would appear on all topic pages, add to a forum, it will appear in all, and so on.

How I would like to use the widgets.

I have a forum based on a music group with 7 members, each member has their own subforum. When viewing a members subforum, I was hoping to be able to target more specific content for that member in the sidebar with the following custom widget blocks:

TAGS - Only display content for that member
GALLERY - Only show images for that member
DOWNLOADS - Show only files for that member

and so on.

Thanks @Marc for the reply.