Subba,
I reread your question and I don't think my suggestion will fully accomplish what you're asking. It will simply apply filters when the app opens. If that's the route you want to go, open the app in Qlik Sense Desktop. Apply your status filter, then make a change to the app so the save button is active. Save the app. You'll see that every time the app opens it will apply your selections. The user will then need to remove all selections to get to the complete set.
Sunny's suggestion will work if you want Safety,Critical,High to show on opening without any selections but you'll need to code the set analysis into every chart expression.
Sunny's code is correct but a little hard to interpret.
Sunny is saying your expression should be "If(GetSelectedCount(Status) = 0, sum({<Status = {'Safety', 'Critical', 'High'}>}YourColumn), sum(YourColumn))"
You don't need to use sum, any aggregation function will work, I'm just using as an example.
Mike
