Please be advised that there's currently no out-of-the-box option to do this in BuddyBoss. Modifications are typically considered custom work, but we are making an exception in this case. Kindly check our Support Policy here: https://www.buddyboss.com/support-policy/. Kindly try adding the following code in your theme files:

1. Go to Appearance > Theme File Editor
2. Under “Select theme to edit”, choose (BuddyBoss Child/Whatever theme is active), then click “Select”.
3. Below Theme Files, select Theme Functions (functions.php).
4. Append the following just before the closing PHP tag “?>”:

remove_action( 'bp_actions', 'bp_members_action_activate_account_custom' );
function bp_members_action_activate_account_custom() {
    if ( ! bp_is_current_component( 'activate' ) ) {
        return;
    }
    if ( is_user_logged_in() ) {
        return;
    }
    if ( ! empty( $_POST['key'] ) ) {
        $key = wp_unslash( $_POST['key'] );
        // Backward compatibility with templates using `method="get"` in their activation forms.
    } elseif ( ! empty( $_GET['key'] ) ) {
        $key = wp_unslash( $_GET['key'] );
    }
    if ( empty( $key ) ) {
        return;
    }
    $bp = buddypress();
    $user = apply_filters( 'bp_core_activate_account', bp_core_activate_signup( $key ) );
    // If there were errors, add a message and redirect.
    if ( ! empty( $user->errors ) ) {
        bp_core_add_message( $user->get_error_message(), 'error' );
        bp_core_redirect( trailingslashit( bp_get_root_domain() . '/' . $bp->pages->activate->slug ) );
    }
    bp_core_add_message( __( 'Your account is now active!', 'buddyboss' ) );
    bp_core_redirect( 'http://buddyboss.local/login/' );
}
add_action( 'bp_actions', 'bp_members_action_activate_account_custom' );

Note: The function bp_core_redirect( 'http://buddyboss.local/login/' ); redirects users to the login page instead of the confirmation page. Please make a backup of your site. 

5. Click “Update File”.