UseTenant TypeFilterAttribute for SaaSKit - https://github.com/saaskit/saaskit/

UseTenantFilter.cs

public class UseTenantAttribute : TypeFilterAttribute
{
    public UseTenantAttribute() : base(typeof(UseTenantFilter))
    {
    }

    private class UseTenantFilter : IActionFilter
    {
        readonly AppTenant _tenant;
        public UseTenantFilter(ITenant<AppTenant> tenant)
        {
            this._tenant = tenant.Value;
        }

        public void OnActionExecuting(ActionExecutingContext context)
        {
            if (context.Controller is ITenantController)
            {
                ((ITenantController)context.Controller).Tenant = _tenant;
            }
            else
            {
                context.Controller.ViewBag.Tenant = _tenant;
            }

        }

        public void OnActionExecuted(ActionExecutedContext context)
        {

        }
    }
}

ITenantController.cs

interface ITenantController
  {
      IAppTenant Tenant { get; set; }
  }

TestActionController.cs

//Using standard controller and returning Tenant within ViewBag
public class TestActionController : Controller
{   
    [UseTenant]
    public IActionResult Index()
    {
        AppTenant tenant = (AppTenant)ViewBag.Tenant;

        return View();
    }
}

TestController.cs

//Using ITenantController interface and setting AppTenant property
[UseTenant]
public class TestController : Controller, ITenantController
{
    public AppTenant Tenant { get; set; }
    
    public IActionResult Index()
    {
        ViewBag.TenantName = Tenant.Name;

        return View();
    }
}