Match values from a list to another list

Hello, I am trying to use a formula in a virtual column to check the contents of a form that a user is completing, with other values already in the same table.
The Table is called ‘Roster Table’. The column that has the enum list is called [Items Rostered].
The [Items Rostered] list can have one or more entries.

this is the formula: IF(IN([_THISROW].[Date], Select(Roster Table[Date], IN(SPLIT([Items Rostered],), [_THISROW].[Items Rostered]))), Yes, No)

The column [Items Rostered] is an enum list.

What i am trying to achieve is that there can be no two entries that share the same date, and one or more of the same values in the [Items Rostered] enum list field.

Someone posted on this many-months old thread just today, what a coincidence!

This might help you with your problem, using the INTERSECT() expression.