Allow logical combinations inside logical combinations

I am trying to add logical combinations that have logical combinations inside but I get the compile error "Have combination of combination". I don't quite understand why this is not allowed.

Do I need to add a special flag for these "complex" combinations? Is there any way of doing this except replacing the logical combination id with its logical combination recursively?

ex:
1:/hi/
2:/hello/
3:/how/
4:/are/
5:/you/
6:/ 1 | 2 /C
7:/ 3 & 4 & 5 /C
8:/ 6 & 7 /C

Expression 8 would become: (1 | 2 ) & (3 & 4 & 5).

It just feels like a natural thing to do with logical combinations.