Custom setting not displying correct picklist values based on the condtion

i have a custom setting called the product and under that, I created two fields called and other is string field BD__c. i want to display picklist value based on string matching record. my custom setting looks like AAA |1,2,6,8 BBB |1,2,6,8 NNN|8 so when string value is 1,2,6,8 it should show AAA, BBB when its 8 it should show NNN, but i can see all the values even if BD__c==8

Here is my apex controller method. can someone suggest me what I am missing

public List < SelectOption > getTR_picklistvalue() {
    system.debug('******Start of getTR_picklistvalue');
    List < SelectOption > options = new List < SelectOption > ();
    options.add(new SelectOption('', '--Select--'));
    Map < String, picklistvalue__c > Prod = picklistvalue__c.getAll();
    List < String > keys = new List < String > (Prod.keySet());
    keys.sort();
    for (String key: keys) {
        if (Prod.get(Key).BD__c == '1,2,6,8')
            Options.add(new SelectOption(Prod.get(Key).picklistvalue__c, Prod.get(Key).Name));
        else
            Options.add(new SelectOption(Prod.get(Key).picklistvalue__c, Prod.get(Key).Name));
        //options.sort();
    }
    return options;

}