SQL Server cross a view with a set based on hierarchy

Question

I have a view in my SQL Server database which basically holds hierarchical information between some records based on id values of type int. A simple representation is as follows:

ID    Parent_ID   
1     NULL  
2     1  
3     2  
4     NULL  
5     4

By using this view I am trying to generate another view. I want all records that derive from ID=1 (which are 1, 2 and 3) to be crossed with a set, while other records (4, 5) be crossed another set. As an example crossing all records that derive from ID=1 with set (1,2) and crossing other records with set 3, I want a view as follows:

ID    Value  
1      1  
1      2  
2      1  
2      2  
3      1  
3      2  
4      3  
5      3