HI Srivaths,
If you have Sandbox where you can play around try this
In SPRO>FSCM>TRM>Transaction manager> General Settings> Accounting > Settings for Position Management > Define and assign Differentiations> Assign folder
Delete the entry for your company code , save and recreate the entry again. Then try to see the migration category or TPM44 directly.
But remember please do it in the sandbox system only. If you are doing it in Dev System , make new Transport for this so the following systems are not affected if something goes wrong.
Also i strongly suggest you create an OSS.
Regards,
Nikhil