I have a separate document found in a binder that contains separate Parts (which in turn contains multiple clauses), and the numbering for each Part resets to 1. How can I force restart the numbering for each of these Parts?
If the Parts themselves are not numbered, the numbering will not reset. Heading/paragraph numbering resets when a new heading/paragraph on a higher level is encountered (by default the level directly above it, but this can be tweaked in the numbering styling).
You can, however, reach the same effect by putting each Part in a separate document in the binder. This ensures numbering restarts at 1 for each Part.