Select Hierarchy Level Example 
The original hierarchy tree is:
M1
M11
M12
M121
M122
M1221
M1222
If level 2 is selected, the two levels below the specified member ID are selected with the member ID itself. The total level number of the subtree including the root node is 3. The following subtree is returned if the member ID is M1:
M1
M11
M12
M121
M122
If level 1 is selected, the one level below the specified member ID is selected with the member ID itself. The total level number of the subtree including the root node is 2. The following subtree is returned if the member ID is M1:
M1
M11
M12
If level 0 is selected, only the specified member ID itself is selected, as a tree with only one node. The following subtree is returned if the member ID is M1:
M1