No, Booking.com does not allow setting a different Minimum Night Stay (MinStay) for derived rate plans. The MinStay restriction must match the base rate plan from which the derived plan is created.
If you want to offer a rate plan with a different stay duration (e.g., 7-night or 30-night minimum stays), you will need to create it as a standalone rate plan instead of deriving it from an existing one.
Example:
If your regular rate plan has a 2-night minimum stay, and you want to offer a 7-night minimum stay for weekly discounts, the 7-night plan must be created independently, not as a derived plan.