Slice filter condition for Parent table based on a field value in the Child table

[candicepelser]

Hey All,

I’d like to add a filter condition to an existing slice.
It should filter the Parent table (that I’m slicing), based on a value in a field from the Child table.

The relationship: There can be Zero or One Child per Parent.
The tables are:
Parent: turtle_interaction (with PK - interaction_id)
Child: turtle_admission (with FK = interaction_id, and filter condition field = trc_outcome)

Requirement: The Slice should provide only the turtle_interaction records that have associated turtle_admission records with trc_outcome = NULL (blank)

In the App, the Referenced Child Table List is called:
Related dbo.turtle_admissions

Here’s my expression attempt, that isn’t quite working:

AND([interaction_date_time] > “01/06/2020 00:00:00” ,([interaction_outcome] = 2), (ISBLANK(‘Related dbo.turtle_admissions’.[trc_outcome])))

Thanks!