How to convert Optical RX Value to dBm Few Value are Ok But Few Value not ok

The easiest way to accomplish this is is a virtual param. This will give you the most flexibility.

Another way of accomplishing your goal is Admin → Config → Edit index page, then find your Pwr param and append || ' dBm' so you end up with something like this:

- label: "'Pwr'"
  parameter: Device.Some.Node.PowerOrSomeOtherParamName || ' dBm'