compare list with variable

i have a variable for exmaple ‘one_two’  and have a list which contains one,two,three,four now i need to find if the values in the list are contained this variable. basically from above exmaple i should get the output( in a variable probably ) as ‘one’ and ‘two’ are found in the variable. how to do this. i am able to compare list with list, but not sure how to compare a list with variable.