Changes to the data in dataset with live connection

[Ivana_Hru]

Hi all,

I am struggling with this. I have a dataset that has a live connection so I understand I cannot change the table, add new column etc. I would like to create a function or measure that would do following: 
- I have column with several values, from those values I want to select one value and assign it a new name and then select all the other values and assign it a different name so I end up with only two values. In excel it would be a matter of filtering out and creating a new column with 2 values but how to do it in Power BI that has limited possibilities to adjust because of the live connection of the dataset?

Thank you all for your ideas.