HTML value support multiple custom field values

I create a custom field AJAX Post filter, its filter values correct way.. Now i need to make it more optional after that it support multiple values of one custom field..

Working This way:

Custom field Key & Value ===> display = 4 ... This is for 1st input others value will be 5,6 and 7.

<div class="display">   
    <li><input type="checkbox" name="display" value="4" class="br"> 4 inch  </li>
    <li><input type="checkbox" name="display" value="5" class="br"> 5 inch  </li>
    <li><input type="checkbox" name="display" value="6" class="br"> 6 inch </li>
    <li><input type="checkbox" name="display" value="7" class="br"> 7 inch </li>
</div>

Required That way:

Custom field Key & Value ===> display = 3.5 .. for first input

<div class="display">   
    <li><input type="checkbox" name="display" value="1.0 - 4" class="br"> Below - 4.0 inch  </li>
    <li><input type="checkbox" name="display" value="4.1 - 5" class="br"> 4.1  - 5 inch  </li>
    <li><input type="checkbox" name="display" value="5.1 - 6" class="br"> 5.1  - 6.0 inch </li>
    <li><input type="checkbox" name="display" value="6.1 - 8" class="br"> 6.1  - above inch  </li>
</div>

Required in More Detail:

when i put value 1 to 4 in custom field then first checkbox filter it.. How to manage in input tag value 1 - 4 that will support custom field values that will also between 1 - 4??

In others words inside input tag value support multiple values.