- Replace: <Your Workspace ObjectID> with your proper value. - Replace <Your In-Progress ScheduleState Value> with your proper value. You can use WSAPI query or other LBAPI queries to find it.
Essentially this query is asking for all snapshots of artifacts which are - of type HierarchicalRequirement and - that have ScheduleState match the value you shall replace for In-Progress, so snapshots in that state. and, - that have _PreviousValues.ScheduleState that is not equal ($ne - see above) that state, so previously were in another state.