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function is not described

get_dashboard_url() WP 3.1.0

Retrieves the URL to the user's dashboard.

If a user does not belong to any site, the global user dashboard is used. If the user belongs to the current site, the dashboard for the current site is returned. If the user cannot edit the current site, the dashboard to the user's primary site is returned.

Hooks in function
Return

String. Dashboard URL link with optional path appended.

Usage

get_dashboard_url( $user_id, $path, $scheme );
$user_id(int)
User ID.
Default: current user
$path(string)
Optional path relative to the dashboard. Use only paths known to both site and user admins.
Default: ''
$scheme(string)
The scheme to use. 'http' or 'https' can be passed to force those schemes.
Default: 'admin', which obeys force_ssl_admin() and is_ssl()

Code of get dashboard url: wp-includes/link-template.php VER 5.1.1

<?php
function get_dashboard_url( $user_id = 0, $path = '', $scheme = 'admin' ) {
	$user_id = $user_id ? (int) $user_id : get_current_user_id();

	$blogs = get_blogs_of_user( $user_id );
	if ( is_multisite() && ! user_can( $user_id, 'manage_network' ) && empty( $blogs ) ) {
		$url = user_admin_url( $path, $scheme );
	} elseif ( ! is_multisite() ) {
		$url = admin_url( $path, $scheme );
	} else {
		$current_blog = get_current_blog_id();
		if ( $current_blog && ( user_can( $user_id, 'manage_network' ) || in_array( $current_blog, array_keys( $blogs ) ) ) ) {
			$url = admin_url( $path, $scheme );
		} else {
			$active = get_active_blog_for_user( $user_id );
			if ( $active ) {
				$url = get_admin_url( $active->blog_id, $path, $scheme );
			} else {
				$url = user_admin_url( $path, $scheme );
			}
		}
	}

	/**
	 * Filters the dashboard URL for a user.
	 *
	 * @since 3.1.0
	 *
	 * @param string $url     The complete URL including scheme and path.
	 * @param int    $user_id The user ID.
	 * @param string $path    Path relative to the URL. Blank string if no path is specified.
	 * @param string $scheme  Scheme to give the URL context. Accepts 'http', 'https', 'login',
	 *                        'login_post', 'admin', 'relative' or null.
	 */
	return apply_filters( 'user_dashboard_url', $url, $user_id, $path, $scheme );
}