Slice based on comparison of selection enumlist and slice-row's enumlist

[generativegeorg]

(Context below) For the value of "Row filter for slice" I was thinking something like:

ISNOTBLANK(
  INTERSECT(
    SELECT(Selections[Selected Departments], [_RowNumber]=1)
    , [Role_Assigned_Departments]
  )
)

but "INTERSECT does not accept a list of list."

I'd like to generate a slice from an enumlist dropdown.
Where tableA contains only one row, with the enumlist to filter by (my selection dropdown on a dashboard)
tableB contains many rows, filtered in a slice
to show only rows where the row's enumlist includes at least one entry matching one on tableA's enumlist.

P.S.

Is it possible to get the rows/values of selected entries on a dashboard view? (interactive dashboard does not seem to work with these many-to-many enumlists/virtual lists)

P.S. 2
tried stuff with CONTAINS() and IN() but I think you'd need a nested loop bc 2 its lists, and I don't see a way to do stuff like 'for each'

[Steve · Accepted solution]

This?

ISNOTBLANK(
  INTERSECT(
    SPLIT(("" & SELECT(Selections[Selected Departments], [_RowNumber]=1)), " , ")
    , [Role_Assigned_Departments]
  )
)

Construct a list from table-column references - AppSheet Help (search for "flatten")