Adam Nowak

Create multiple sidebars, just name your new sidebar the same name as the Buddypress Component and it will show up when that component is displayed. So you can have separate sidebars for ‘Activity’, ‘Members’, ‘Groups’, etc. You can also name a sidebar the same name as any page and that sidebar will automatically show up on that page. Prefabricated sidebars include Home and Blog. The Blog sidebar will appear on single and archive blog pages.

Buddypress Sidebar

This plugin enables you to have multiple sidebars for Buddypress. Create new sidebars that are unique to each page.

Chandan Garg

Are you looking for easy and robust way to manage your sidebar areas dynamically from wordpress admin ? CG Dynamic Sidebar is a suite of components which helps you to create your custom sidebar area and allows you to add upto 20 different sidebar areas which you can use them in your website.
CG Dynamic Sidebar is focused on ease of integration and ease of use. It is deliberately powerful plugin using which users can create their own sidebar easily without having any technical knowledge of how to create custom sidebars. 
Usage :
<pre> <?php dynamic_sidebar("my-custom-sidebar"); ?> </pre>
<h3>Usage</h3>
While adding your sidebar area you have option to keep your sidebar id, this id will be used to display your custom sidebar in page/post. 
If you have added a new sidebar with below details : 
Sidebar Title : My Custom Sidebar 
Sidebar id : my-custom-sidebar
Then, to use this sidebar, you have to use below PHP code in your sidebar.php or anywhere you want to show this sidebar.
<pre> <?php dynamic_sidebar("my-custom-sidebar"); ?> </pre>

CG Dynamic Sidebar

CG Dynamic Sidebar helps you to add/create multiple sidebar areas in your admin widgets screen. Easy Installation and Easy management.

Buddypress Sidebar vs CG Dynamic Sidebar