How can I add members Sliders in buddyboss message page?

Question

I want to add all members slider before the message box. Please see the image. In the red area, I want to add all members slider. I think buddyboss already have this widget.

Bussyboss message page, Where to place the members slider

function test_nouveau_hook_before() {
    echo 'This content is displayed before the compose content.';
}
add_action( 'bp_before_messages_compose_content_box', 'test_nouveau_hook_before' );