Is it possible to nest bitfields?

[ukasz]

I am trying to describe 8B word as a bitfield with multiple fields in it.
The problem is that some of the fields in it are bitfields as well.
When I try to nest bitfields inside a struct it's size becomes 10 bytes instead of 8, so the only way
to deal with it is use a single bitfield and ignore valid decoding of inner bitfields.
Is there any existing pattern that deals with similar problem?