Can I replace between with amid here?
The engineers need to design the relationship between these function blocks.
Turning into
The engineers need to design the relationship amid these function blocks.
Can I replace between with amid here?
The engineers need to design the relationship between these function blocks.
Turning into
The engineers need to design the relationship amid these function blocks.
No.
Between is used in sense (3) from http://www.merriam-webster.com/dictionary/between:
a : from one to another of
b : serving to connect or unite in a relationship (as difference, likeness, or proportion)
whereas amid has only its primary meaning (from http://www.merriam-webster.com/dictionary/amid):
: in or into the middle of (something)
The use of amid in your sentence therefore give us the sense that the engineers must be physically standing in the middle of a group of function blocks while they design the relationship (which does not necessarily relate to the function blocks at all), which is clearly not a reasonable meaning.