Populate detail grid with data already returned from parent grid data source


I want to make a detail grid where the necessary data is already present from the parent grid data source.
Parent grid lists TypeA
Detail grid lists TypeB, which is TypeA.arrayField: [TypeB]

The data source that feeds the parent grid already returns all of the data in TypeA.arrayField, and I don’t want to create a second, separate data source because:
#1 The data being returned isn’t persisted (e.g. can’t fetch on TypeB)
#2 It’s already a lengthy API, so running it again to return records of TypeB is not performant

My intuition was to do something like the following in the data field of the detail grid:

data: {
    collection: "'{{ record.data.arrayField }}'"

but that didn’t work.

Any suggestions or pointers?