In Tableau I want to Create different levels on the basis of Percentage

Version 1

    I have a situation where I have an measure named as ILSS we get ILSS using formula.

     

    So we have ILSS calculated field. Keeping this calculated field in mind. For each product I want to keep them in Different levels such as L0,L1,L2,L3,L4.

     

    IF ILSS is less then 20% then L0

    elseif ILSS 20% to 40% then L1

    ILSS 40% to 60% then L2

    ILSS 60% to 100% Then L3

    ILSS >100% then L4

     

    these level I want to show on graph with Legion

     

    What should I use for these level Should I create parameter or create additional calculated field for each level to show it on graph.

     

    can someone suggest me the logic.

     

    Thanks in advance