Answer
This is a genuine limitation of Lobby navigation rather than a missing configuration option — navigating from a Lobby element to a target screen doesn't carry a Saved Search's Sum/Group-By settings through to the opened window. A partial workaround: create a separate copy of the target screen configured to run as its own independent process/window, with its own default Saved Search already containing the desired Sum/Group condition pre-applied on that copy specifically — though this separate-process copy won't pick up any of the Lobby element's own click-through parameter filtering the way the original in-place navigation would.