Update tenants.blade.php

source/docs/v3/tenants.blade.md

@@ -130,6 +130,20 @@ You may access the current tenant using the `tenant()` helper. You can also pass
 
 Alternatively, you may typehint the `Stancl\Tenancy\Contracts\Tenant` interface to inject the model using the service container.
 
+## Accessing the central application {#accessing-the-central-application}
+
+When your code executes in the context of a tenant, you may access the central application context by using the `tenancy()->central($callback)` function.
+
+For instance, if you want to retrieve the list of users of the central application when the code executes in a tenant's context, you may write:
+
+```php
+// Here we are in the tenant's context. User::all() would return the current tenant's users
+$centralUsers = tenancy()->central(function () {
+    // Here we are in the central context
+    return User::all();
+});
+```
+
 ## Incrementing IDs {#incrementing-ids}
 
 By default, the migration uses `string` for the `id` column, and the model generates UUIDs when you don't supply an `id` during tenant creation.