def group_consecutive_duplicates(nums: list[int]) -> list[list[int]]:
    n = len(nums)
    count, results = 1, []
    for i in range(n):
        if i < n-1 and nums[i] == nums[i+1]:
            count += 1
        else:
            results.append([nums[i]]*count)
            count = 1
    return results