@Html.Partial("OtherView.cshtml", Model)

or

await Html.PartialAsync("OtherView.cshtml", Model)

is the way to include a partial view. After Asp.NET 2.1, the preferred way is to use a partial tag helper:

<partial name="OtherView" />

Details on how relative paths are resolved and more at https://learn.microsoft.com/en-us/aspnet/core/mvc/views/partial?view=aspnetcore-9.0