Can you please elaborate your issue?
Now you can see all the product categories in the sheet. If you will apply filter product sub category and select some values then it will affect to the product category. So I want if any filter we will apply to the sheet , product category values shown should be constant .
Create new sheet and add constant values only in that sheet.
Drag that sheet into dashboard.
When you create others views and adding filter then don't select constant sheet.
It sounds like, within the same sheet, you want the categories to show even if all their subcategories have been filtered out. I don't see how Tableau can do that. At that point, you're in a paradox of asking Tableau to both eliminate and show the category. If you just need the list of categories (rather than an empty one with no subcategory and no aggregate), then like Sankar said, you can make a separate sheet. It doesn't have to have constants; it can be based on the data but not filtered by your dimension filter for your other sheet in the dashboard.
I have one data source filter, so I do not want to remove the data source filter.