If I choose Picklist Field name is
Rating_Score_c (1,2,3),(4,5,6),(7,8,9) then in another field Rating_Grade_c show the grade A,B,C. ie., means
when i choose/pick any number (1,2,3) then it shows "A" in "Rating_Grade_c",
when i choose/pick any number (4,5,6) then it shows "B" in "Rating_Grade_c".
when i choose/pick any number (7,8,9) then it shows "C" in "Rating_Grade_c".