The indicator can apply any trading instrument chart to the main one. An added symbol is scaled depending on the amount of bars currently visible on the chart. This allows you to visualize the arbitrage trading possibilities on a pair of symbols (assets).
If you need a reverse correlation, you can apply a reversed price. For example, you can apply the USDGOLD chart (instead of GOLDUSD) to the USDCAD one. In this case, the price is reversed and GOLDUSD is re-scaled appropriately.