Data validation with conditional list by input formula

Hi,
I want to make a dropdown list by data validation, and the data source by conditioning with a formula.
I try to input the "IF" formula and it works fine, but when I input =UNIQUE(FILTER(Table1[A],Table1[B]=C6)), it shows an error.

I try to make the dropdown list that refers to the specific cell value, for example, C6, and the list will only show after filtering that refers to the C6 value.

Have any other suggestions or alternative ways to do this Data validation with the conditional list?

Hi, I'm sorry.
Here is the attachment. Data validation with conditional list.xlsx

I want to create data validation with a conditional list by inputting the formula instead of just referring to the other table list.
In my example, I have created a filtered list based on the specific criteria for validation reference, but if I don't want to create the reference list and just input the formula in the data validation column, is it possible?

cell D5 Data validity formula

Formula:

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cell E5 Data validity formula

Formula:

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Hi wk9128 ,
Thank you very much for providing the solution.

I remove the "Unique" formula for D5 and it just work well.

You're Welcome. Glad to help . Thank You for the feedback.

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