SSRS Multi-Value Parameter Not Selecting default value

Question

How to set Default value in multi-value parameter when one of the parameter is not present in the Available Value In SSRS Report

pleas Look this Image

I have Multi-Value Parameter Name "Student Id" , available value are "1,2,3,4,5,6,7".

Now I am Setting Default value 1,2 then multi parameter Selected the Student id 1 and 2.

But issue is when Set student id 1 and 10 from Report 2 to Report, it is not selecting any thing. Its because of Id 10 Which is Not in Present in value.

Answer 1

I fixed this By using the LookupSet() method in SSRS

=LookupSet(Fields!ClassId.Value,Fields!ClassId.Value,Fields!StudentId.Value,"StudentDataSet")

its checking the value in Data Set and giving me Id like Student Example. if value is 1,2,10 then it give me 1,2,1,2,1,2 but i am not why its giving 1 and to multi time but its working for me Thanks. I am new in SSRS can you Explain me one more time so it will work for me ,or i am doing something wrong