Can anyone provide query using mgmt$ view for tablespace reporting?

Need to setup Report in a way that it provides list of tablespaces of all the targets discovered in EM above say threshold of 75% used.

Currently i am using below query but unable to modify it as per the requirement, please help :

select * from

   ( select target_name,KEY_VALUE NAME

  ,decode(column_label,'Tablespace Allocated Space (MB)' ,'total_space'

            ,'Tablespace Free Space (MB)','free_space'

            ,'Tablespace Used Space (MB)','used_space'

            ,column_label) as column_label

            ,value

    from sysman.mgmt$metric_current

   where COLUMN_LABEL IN('Tablespace Allocated Space (MB)','Tablespace Used Space (MB)','Tablespace Free Space (MB)')