您的问题的本质已在此线程中提出并涵盖:

这是一个可供下载的示例文件(在 M 和 DAX 中都有两种方法):

M 默认切片器值.pbix

您可以通过添加计算表完全在 DAX 中制作 DimStore 表:

DimStore_DAX =汇总列(销售[商店],"销售", [销售],"Rank", RANKX ( ALL ( Sales[Store] ), [Sale] ),"StoreName", IF ( RANKX ( ALL ( Sales[Store] ), [Sale] ) = 1, "最大的商店", VALUES ( Sales[Store] )))

I have a requirement that the selected value in slicer must be valid.

Let us suppose if I select a value in Store slicer and that store gets deleted from the company. The slicer will still show its name with no data in visuals interacting with the slicer.

Default Value Selected

Updated Slicer Value Manually

But I want only the relevant store selected in my Store slicer. I know its slicer's property to retain the value which is set in it while publishing the report, but is there any workaround for it.

The essence of your question has been asked and covered in this thread:

Initial value of Power BI slicer based on another slicer choice

The answer is NO, but I can propose a workaround.

1. In the dimension table with stores, add a calculated column Rank which will determine the store with the highest sales. You may use RANKX function for that.
2. Add StoreName calculated column which returns the text value "The biggest store" (or "Top 1" - or whatever) and original store names for all the other stores. Use IF.
3. Put the column StoreName which contains "The biggest store" value to the slicer.
4. Add a visual (card, table) where you will display the original name of currently selected store.
5. Sort the column StoreName by Rank column designed for that purpose so that The biggest store will float up to the top position in the slicer. Here is how to sort the column by another column.

Since there is always a store with the highest sales you may always have that value ticked in the slicer and it will always show data.

In this example "The biggest store" is "Store for girls". I keep it selected on the slicer. Then I remove all the records of that store from fact table. Apply. And the slicer is still selected as "The biggest store" but now the biggest store means "Store for ladybirds".

Here is a sample file for download (with both approaches in M and DAX):

M Default Slicer Value.pbix

You can make DimStore table completely in DAX by adding calculated table:

DimStore_DAX = 
SUMMARIZECOLUMNS (
    Sales[Store],
    "Sales", [Sale],
    "Rank", RANKX ( ALL ( Sales[Store] ), [Sale] ),
    "StoreName", IF ( RANKX ( ALL ( Sales[Store] ), [Sale] ) = 1, "The biggest store", VALUES ( Sales[Store] )
    )
)