NAMEOF slicer select with multiple dimensions

Hi guys!

Let's say I have such measure:

Parameter = {
    ("Customer Name 1", NAMEOF('Customer 1'[Cust Name]), 0),
    ("Customer Name 2)", NAMEOF('Customer 2'[Cust Name]), 1)
}

I use this in slicer and in matrix as a row. Depending on selection in matrix it will show me one, the other or both at once in a hierarchy (one under another).
That's great, but is there a way to tweak it so I have a slicer with True/False option that depending on choice, when "True" selected, it will show the Customer 1'[Cust Name]). So nothing fancy, just as above one.
BUT if False selected, it will show both in a hierarchy, 'Customer1'[Cust Name] and when drilled down, 'Customer 2'[Cust Name]? So as if both were selected in the original slicer.
I guess the same result would be if it either shown/hid 'Customer2'[Cust Name] but no clue which is easier.
Thank you!