I would even say, don’t call it ‘search’ – call in ‘view’ (or something)
If search results are editable, and all the found items and their sub-items are accessible and editable, then by just entering a few search keywords you can have a brand view of many lists and work on them.
examples:
- work on all lists due today or tomorrow
- work on lists marked @urgent
- Work on all lists containing name/expression
… etc …
If those searches are then bookmarked, you have a super-useful workflow that give much order to a database with many lists.