Yes you can select "Always One Selected Value" option from list box properties. I feel you might not be able to select that since it's not highlighted for you. Am I right? to get that highlight you first create your list box and select one value first then go to the properties. You'll get that option enable.
I hope this will help you, if not please let us know.
Ok. Then select a value from the dimension field value and check on always selected one value.
on based on that dimension field which you create an expression create that list box will also and select that value which having in both list box
then delete the Core dimension list box
see the example attached
i have Year field i put expression to get limited record
then select the field value in year dimension which also present in creating new list box value.
then on Year field check on always selectd one value and delete that list box
Hope it helps you .
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