motors.h

#include <Adafruit_TiCoServo.h>

class MotorState {
  private:
    Adafruit_TiCoServo _servo_backdrop;
    Adafruit_TiCoServo _servo_stage;
  public:
    MotorState();
    void init(Adafruit_TiCoServo *servB, Adafruit_TiCoServo *servS);
    void updateMotors(int backdrop, int stage);
};

MotorState::MotorState(){}

void MotorState::init(Adafruit_TiCoServo *servB, Adafruit_TiCoServo *servS){
  _servo_backdrop = *servB;
  _servo_stage = *servS;
}


void MotorState::updateMotors(int backdrop, int stage){
  int s = constrain(map(stage, 0, 1023, 500, 2500), 500, 2500);
  int b = constrain(map(backdrop, 0, 1023, 500, 2500), 500, 2500);
  _servo_stage.write(s);
  delay(20);
  _servo_backdrop.write(b);
}

Workingclass.ino

#include "motors.h"
#include <Adafruit_TiCoServo.h>

Adafruit_TiCoServo servo_backdrop;
Adafruit_TiCoServo servo_stage;

MotorState motorState;

void setup() {
  // put your setup code here, to run once:
    
    servo_backdrop.attach(9);
    servo_stage.attach(10); 
    motorState.init(&servo_backdrop, &servo_stage);
}

void loop() {
  // put your main code here, to run repeatedly:
    motorState.updateMotors(analogRead(A0), analogRead(A1));

}