How to set variable string to Object selector?

Question

My Object has a lots of parameter with location, like USA JAP ...

How to concact my object parameter value with String variable

Here is my condition:

let loc = '';
if (location === 'USA') {
  // the value setting from my Object parameter
  // different location with different value
  loc = 'usaLocationValue';
} else if (location === 'JAP') {
  loc = 'japLocationValue';
} else if() {
  // etc...
} else {
  // ...
}

// and then filter it
let filterLocationValue = [];
filterLocationValue = MyObjectArray.filter(value => {
  return value.loc > 0; // it doesn't work
});

I still try return value.${loc} > 0 (with drop symbol), it doesn't work too.

If I have to set if condition to decide what parameter to be used first. How to achieve it ?

Any help would be appreciated. Thanks in advance.