Display dashboard other than admin user

You must assign admin capability to custom role.

You can assign ‘manage_options’ capability for user role plugin.

OR

Add following code in custom plugin or functions.php file of child theme, and reactive plugin/theme after code is added.

$result = add_role(
    'staff',
    __( 'Staff' ),
    array(
        'manage_options' => true
    )
);