maybe you should set for all or just for t1/t2.. fields an Alias like

t1.CODE_CLOCK_ID as CODE_CLOCK_ID_s26,
t1.COMPANY_CD as COMPANY_CD_s26,
t1.GROUP_SEGMENT_L1 as GROUP_SEGMENT_L1_s26,
t1.GROUP_SEGMENT_CD as GROUP_SEGMENT_CD_s26,
t2.CODE_CLOCK_ID asCODE_CLOCK_ID_s27,
t2.COMPANY_CD as COMPANY_CD_s27,
t2.GROUP_SEGMENT_L1 as GROUP_SEGMENT_L1_s27,
t2.GROUP_SEGMENT_CD as GROUP_SEGMENT_CD_s27

Greets