Hi Paula! Thanks for your question.

Old leases can be archived using the Archive Leases function (knowledgebase article ID 22442). However, all revisions for the lease must be in Historical or Canceled status before any of the lease revisions can be archived. Because they all share the same lease ID, those records have to stay together. Which also means you should not delete an amended lease from Change Lease as it could create some broken records and may result in a file fix.

If you change those Terminated leases to a Historical status (knowledgebase article ID 28012), it will at least remove them from the selection lists in the tasks, but they will remain in Change Lease.

I recommend you submit an enhancement request for the ability to condition or filter in Tasks > Manage Leases > Change Lease so you can "hide" those old lease revisions. You can submit enhancement requests in the software from the Help menu, Web Resources (or Sage Timberline Office on the Web), Submit Enhancement Requests.