Need Alternative for 'Value' function

Just to fully understand, can I confirm a few things -

I am assuming " Process_level " is the name of a colmn? so it would be something like, Table1[Process_level] ?

Are you adding to this to a table of visual, then [Process_level] this being used in a slicer?

The problem is that values returns a table, a distinct list of all values. So if you have selected multiple, you are asking if a table equals the string value of "K10 Invoiced". SELECTEDVALUE could do the trick, and I would use a variable:

Year-Month =
VAR _Process_level =SELECTEDVALUE ( [Process_level] )

RETURN

    IF (
        _Process_level = "K10 Invoiced",
        IF (
            MONTH ( TODAY () ) > 3,
            ( MONTH ( TODAY () ) - 3 )
                * [Targets],
            ( MONTH ( TODAY () ) + 9 )
                * [Targets]
        ),
        [Targets]
    )