This feature is deprecated in Identity Server 5.3.0 release. The alternative to this is using database level table partitioning. Since all commercial databases support table partitioning as a first class feature, it is recommended to use table partitioning to partition required tables including IDN_ACCESS_TOKEN table.
You can configure the Identity Server instances to store access tokens in different tables according to their user store domain. This is referred to as user token partitioning and it ensures better security when there are multiple user stores configured in the system. For information on configuring user stores other than the default one, see Configuring Secondary User Stores.