code: function isMatchingPath(parentIndex, indexOrKey) {
              var pane = lxSelect.choicesViewSize === 'large' ? lxSelect.panes[parentIndex] : lxSelect.openedPanes[parentIndex];
  
              if (angular.isUndefined(pane)) {
                  return;
              }
  
              var key = indexOrKey;
              if (angular.isObject(pane) && angular.isNumber(indexOrKey)) {
                  key = (Object.keys(pane) || [])[indexOrKey];
              }
  
              if (parentIndex === 0) {
                  return _findIndex(lxSelect.matchingPaths, key) !== -1;
              }
  
              var previous = toggledPanes[parentIndex - 1];
              if (angular.isUndefined(previous)) {
                  return false;
              }
  
              return _findIndex(lxSelect.matchingPaths, previous.path + '.' + key) !== -1;
          }
docs: Check if a path of a pane is matching the filter.
  
  @param {number}        parentIndex The index of the pane.
  @param {number|string} indexOrKey  The index or the name of the item to check.