Project team members having Manage iModel Versions permission can hide Named versions which are not expected to be viewed by all project members.
Go to Named versions list to hide a Named Version:
The purpose of this feature is to hide the unexpected Named versions on iModel Manager service so people would not open these Named versions on Design Review by accident.
However, some features or services, like Version compare of Design Review or Design Validation, will continue displaying the Hidden Named versions even if they are hidden and people can still use them if needed.
Moreover, project members can make sure that the hidden Named versions could still be displayed on iModel Manager service by explicitly selecting the following option:
The selected option will be applied only for the project member who explicitly set this this setting.