remove duplicates with commas using dax

Is this what you are looking for?

Sample PBIX file attached

https://1drv.ms/u/s!AiUZ0Ws7G26RiTP7l9ywzl80goTu?e=BmmNwt

it would be better if you do it in power query

to know how to do it in power query watch my video

https://1drv.ms/v/s!AiUZ0Ws7G26RiTSEuVSwoP3RLq-s?e=fln8s9

= Text.Combine(
List.Distinct(
Text.Split([pro],",")),", ")