RMAN Tablespace Point-in-time-recovery

I need to recover a tablespace called "SBSECD01_MDS" (point-in-time).I need to determine and resolve dependencies.

select obj1_owner, obj1_name, obj1_type, ts1_name, ts2_name from sys.ts_pitr_check where (ts1_name = 'SBSECD01_MDS' and ts2_name != 'SBSECD01_MDS') or (ts1_name != 'SBSECD01_MDS' and ts2_name = 'SBSECD01_MDS');

own1 name1 obj1type ts1_name ts2_name
--------------- -------------------- -------- ------------------------------ --------------------
SBSECD01_MDS MDS_PATHS_N7 INDEX SBSECD01_MDS -1

so I can see index SBSECD01_MDS.MDS_PATHS_N7 's ts2_name is "-1".reason: Domain/Functional Indexes not supported...My question,

1, what means ts2_name?

2. what means "-1"? (it looks not like a tablespace name)

3. in this case, Can I perform a successful TSPITR?

If not, how can do to make a successful TSPITR? (do I need to drop that index first, then recreate it after recovery?)