Duplicate of this issue.
I'm playing on the modpack called "Mechanical Mastery".
This is my setup:

In the chest(1) are multiple items(iron, aluminum, copper and some junk).
The machine(2) must only be given copper and nothing else to operate.
The machine(3) must only be given iron or aluminum and nothing else to operate.
Here is the pipe configuration for the pipe extracting items from the chest:


And here is the configuration for the other pipe:

The issue:
All items that are in the chest(1) still go through the pipe to machine(2).