Help: Data filter expression for filtered dashboard

[EmadK]

I have a filtered dashboard that uses quick edit columns to display data from a table.

I have two customer types: Staff and Student

Isnotblank(
Any(
Select(Filter[ID],
AND(
DATE([_Thisrow].[Date & Time])>=[Start Date],
DATE([_Thisrow].[Date & Time])<=[End Date],
[_thisrow].[Customer Type]=[Customer Type]
))))

I want to display data for both customer types when none of the enum is selected.

How can I change the expression to achieve this?

Thakns!