As you have asked for the further studies after Master of Business Administration (MBA) course, I am giving you information about it, check below for the details
I am mentioning some of the course which you can pursue after MBA

Executive MBA
MCA
PGDCA
CFA - Chartered Financial Analyst
CS
Ph.D. Management Studies
M.Phil. (Statistics)
Ph.D. (Business Management)
Ph.D. - Business Administration
Ph.D. in Management
Post Graduate Diploma in Human Resource Development
PGPSCL
PGDMLM
Post Graduate Diploma in Logistics and Shipping
Post Graduate Diploma in Logistics and Retail Management
Certificate in Statistical Methods and Applications
DBA - Doctor of Business Administration
NCFM - NSE's Certification in Financial Markets
ICWA or any short term course for specialization in financial planning
Postgraduate Diploma in Management E-Biz
Graduate Diploma in Public Procurement (GDPP)
Post Graduate Diploma in Risk and Insurance Management
CA - Chartered Accountancy
CPI Certified CSR Auditor and Lead Training Program
Diploma in Human Resource Development
PG Diploma in Applied Ergonomics
Fellow Programme in Management (FPM)
Management Development Programme (MDPs) - XLRI
Certificate Programme on Capital Markets (CPCM)
PGDCMM
Certified Derivatives Specialist (CDS) Course
NISM-Series-V-A: Mutual Fund Distributors Certification Examination
Certified Bank Manager Programme (CBM)