Custom Column formula

I wanna make a new custom column in Power Query with a variable called x.

The formula should be something like this:

if [Semester] value is equal to 'S22' then x = y

else if [Semester] not equal to 'S22' and [Scheme] in (#"Course data") then x = y

else x = y

I’ve no idea how to write the formula so that it works as I wish. 

Any help is appreciated!