I have to highest two word in the columns. It should have the maximum two words combination. I have attached the excel for reference.
So which word pairs do you want returned from...
research and operations analyst
To me, it seems that there are two 2 word titles there... Research Analyst and Operations Analyst your original data is fraught with such things.
Or, is that not important? And how do you want to treat the word "and"???
OR... is what you're really asking for is to pair every combination of individual unique words in a job title and then do a count? (I still recommend removing the word "and" there).