Calling a function that is outside of a class from inside the class

I have an Arduino sketch with a timer interrupt class and would like to place the TIMER2Services() function in the TimerTwoTest.ino file for easy access. On compile I get a multiple definition of tmb2 error in the .ino TIMER2Services() function. I have tried all the variations I can think of but no luck. Is there a way to do this?

TimerTwoTest.cpp.o: In function TIMER2Services()': D:\Arduino157/TimerTwoTest.ino:41: multiple definition of tmb2'
TimerTwo.cpp.o:C:\Users...\build8577138580185682113.tmp/TimerTwo.cpp:10: first defined here
collect2.exe:

TimerTwo.h:
class Tmb2
{
public:
void initTIMER2(unsigned int Hz, unsigned int ulPeriod);
void resetTIMER2(unsigned int Hz, unsigned int ulPeriod);
TIMER2_TYPE getPeriodTIMER2(void);
void activeTIMER2 (void);
private:
}tmb2;

TimerTwo.cpp:
extern void TIMER2Services(void);

[this function is line 10 for the error]
void Tmb2::initTIMER2(unsigned int Hz, unsigned int ulPeriod){ //setperiod and enable interrupt
if (Hz){
ulPeriod = 1000/Hz; //if Hz > 0 use frequency microseconds
}
Timer2.attachInterrupt(TIMER2Services).setPeriod(ulPeriod).start();
}

TimerTwoTest.ino:
volatile unsigned long burpCount = 0;

//This routine services the interrupt
void TIMER2Services(void){
burpCount++;
}

You’ve created an object in header file:

.
.
.
    }tmb2; // <<<< replace this by "};"

tmb2 has to be created e.g. somewhere in the main source code.

Moving Tmb2 tmb2; to the .ino solved the problem. Thanks