return RedirectToAction("Action1", "YourControllerName");

public ActionResult Action2(string backUrl)
{
    if (string.IsNullOrEmpty(backUrl))
    {
        throw new ArgumentNullException("backUrl");
    }
    ViewBag.ReturnUrl = backUrl;
    //your work
    return View();
}

[HttpPost]
public ActionResult Action2(YourModel model, string backUrl)
{
    //your work
    return Redirect(backUrl);
}

...
@Html.ActionLink("text", "Action2", new { backUrl = Url.Action("Action1") })
...

...
<input name='backUrl' type='hidden' value='@ViewBag.ReturnUrl' />
...