#include <stdio.h>
#include <stdlib.h>

struct number1
{
    int number;
};

struct number2
{
    int number;
};

struct number3
{
   struct number1 *num1;
   struct number2 *num2;
};

void num(struct number1 **numb1, struct number2 **numb2);

int main()
{
    struct number3 *numall = malloc(sizeof(struct number3));

    num(&numall->num1, &numall->num2);
    printf("%d %d", numall->num1->number, numall->num2->number);
    free(numall);
    return 0;
}

void num(struct number1 **numb1, struct number2 **numb2)
{
    (*numb1)->number = 3;
    (*numb2)->number = 2;
}