Excel formula conversation into Dax formula between two files

Question

I am tried all my research to convert this excel formula into Dax formula but was unsuccessful need help to get it corrected.

Here is the excel formula I am using to get the average rating between two files data using 4 criterias like Control I'd, entity name, activity code and risk code average rating. For which I am using Excel formula Iferror(average(if('Rmf rating (dfin)'!F:f=p5,if(isnumuber(search("|"&M5&"|","|"&'rmf rating dfin)'!b:b&"|")),if(isnumuber(search("|"&o5&"|","|"&'rmf rating (dfin)'!d:d&"|")),if(isnumuber(search("|"&n5&"|","|"&'rmf rating (dfin)'!e:e&"|"))'rmf rating (dfin)'!h:h))))),"na")

Here rmf rating sheet is different file which I have added to the pbi and main sheet called assessment where I am trying get the average rating.

Thanks for your help!

Regards Suresh