I have list of issues which contain certain set of fields (6 custom fields) these fields can be have values only "A"or "B". the my question is how can I filter those issues if one these field have a value "A". let say for a example these custom fields are cus_field1,cus_field2,cus_field3,cus_field4,cus_field5,cus_field6 and if one these field have certain value how can I filter those issues?
I am not sure, do you mean how to use an 'or' clause? As I understand, a simple "cus_field1=A or cus_field2=A or cus_field3=A or cus_field4=A or cus_field5=A or cus_field6=A" should solve your problem, isn't it?
According to the reference, I couldn't find any possibility to combine different fields, so you have no other choice but specify the A filter value for each custom field...
https://confluence.atlassian.com/jira/searching-for-issues-185729570.html