#include <util/atomic.h>

// https://forum.arduino.cc/t/manipulate-multiple-pins-with-portd/974951/15?u=dougp

void setup() {
  // suggested by @westfw
  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
    uint8_t tempv = PORTD & ~0xF0;
    PORTD = tempv | 0xC0;
  }

  noInterrupts();
  PORTD &= ~0b11110000; // clear bits 7-4, bits 3-0 unchanged
  PORTD |=  0b11000000; //   set bits 7 and 6, bits 5-0 unchanged
  interrupts();

  // suggested by @johnwasser
  byte DesiredValue = 0b1010;
  PIND = (PORTD ^ (DesiredValue << 4)) & 0b11110000;
}

void loop() {
}