When using 'nested criteria', if you add a criteria to the nested Group, when you select a concept set of the new child (the one added to the nested criteria), the selected concept set overwrites the parent's concept set selection.

Steps to reproduce:

1. New cohort -> Add two concept sets to the Cohort Definition.
2. Add an entry event (Example Condition Occurrence)
3. Assign the first concept set to the Condition Occurrence entry event
4. Add a Nested Criteria to Condition Occurrence
5. Add a Drug Exposure Criteria
6. Select the other concept set for the Drug Exposure
7. Bug: Observe that the parent (Condition Occurrence) has their selected concept set changed, and the child's still has 'select concept set'.