DOn't make complicate in your query. Select a particular block values to CTE and Join in your insert statement. It will be better.
For eg.
SELECT distinct
OPB_MAPPING.PROJECT_ID,
OPB_SUBJECT.SUBJ_NAME SUBJECT_AREA,
OPB_SUBJECT.SUBJ_ID SUBJ_ID,
OPB_MAPPING.MAPPING_NAME MAPPING_NAME
FROM dbo.FD_INFA_OPB_MAPPING OPB_MAPPING
inner join dbo.FD_INFA_OPB_TDS OPB_TDS
on OPB_TDS.MAPPING_ID = OPB_MAPPING.MAPPING_ID
and OPB_TDS.VERSION_NUMBER=OPB_MAPPING.VERSION_NUMBER
inner join dbo.FD_INFA_OPB_WIDGET_INST OPB_WIDGET_INST on
OPB_WIDGET_INST.MAPPING_ID=OPB_MAPPING.MAPPING_ID
and OPB_MAPPING.VERSION_NUMBER = OPB_WIDGET_INST.VERSION_NUMBER
inner JOIN dbo.FD_INFA_OPB_TARG OPB_TARG on
OPB_TARG.TARGET_ID=OPB_WIDGET_INST.WIDGET_ID
inner JOIN dbo.FD_INFA_OPB_SUBJECT OPB_SUBJECT on
OPB_SUBJECT.SUBJ_ID=OPB_TARG.SUBJ_ID
AND OPB_WIDGET_INST.WIDGET_TYPE = 2
AND OPB_MAPPING.REF_WIDGET_ID = 0
AND OPB_MAPPING.IS_VISIBLE in(1,2)
AND OPB_TARG.IS_VISIBLE in( 1,2)
AND OPB_MAPPING.PROJECT_ID= -511779242
make this block to CTE and Join.
I Hope it will help for you.